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247 Cards in this Set
- Front
- Back
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What is a mol? |
It is the amount of substance that contains as many aroms as there are carbon atoms in exactly 12g of carbon-12 isotope |
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Describe the influence the heaviness of atoms has on the amount of substance of mol? |
The heavier the atoms the smaller the amount of substance to equal one mol |
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What is molar mass? |
It is the mass of one mole of a substance. This is essentially the relative atomic mass or the molecular mass |
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What are the units of molar mass? |
gmol-1 |
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If the RAM of Na is 23.0 what is the molar mass? |
23.0 gmol-1 |
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If the RAM of CH4 is 16.0, what is the molar mass? |
16.0 gmol-1 |
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What if the mass of one mole of Carbon if it has an Ar of 12? |
12g |
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What if the mass of two mole of Carbon if it has an Ar of 12?
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24g |
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What if the mass of half a mole of Carbon if it has an Ar of 12?
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6g |
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What is the equation involving mass, moles and moleclar mass? |
mass = number of moles x molar mass |
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What is the symbol for mass? |
m |
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What is the symbol for moles? |
n |
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What is the symbol for molecular mass? |
M |
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What significant figures are used in mole calcualtions? |
3 significant figures |
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What is the name given to the number of atoms in 12g (1 mole) of carbon 12? What is the symbol? |
Avogadros constant Na |
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What is the definition of the empirical formula? |
It is the lowest whole number ratio if atoms of each element in a coumpoundq |
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What is the molecular formula? |
A formula that shows the number and type of atoms of each element present in a molecule |
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What is the acronym for the empirical formula? |
M - Mass A - Ar D - Divide (the above) R - Work out whole number ratio |
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Describe the appearance of hydrated salts? |
They are usually coloured crystals |
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What are many coloured crystals? |
Hydrated salts |
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What is a hydrated salt? |
Where water molecules are part of the salts crystalline structure |
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What is the water in the crystalline sturcture of salts also known as? |
The water of crystalline |
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What happens when you heat a hydrated salt? |
It becomes anhydrous (dehydrated) |
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What colour is copper sulfate? |
Blue |
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What happens when a hydrated salt becomes anhydrous? Describe the last stages of removing water? |
The crystalline structure is lost and a white powder remains. It is very difficult to remove the last traces of water |
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What is a stoichiometry of a reaction? |
The balancing number of the equation gives the ratio of moles that react. It is this that is the stoichiometry of the reaction |
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What does the balancing number of an equation give? |
The ratio of moles that react, this is called the stoichiometry |
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When does stoichiometry only apply? |
When the equation is balanced |
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What do chemists use balanced equations to find? |
1. The quantities of reactants required to prepare a required quantity or a product
2. The quantities of products that should be formed from certain quantities of reactants |
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What is the maximum amount of product possible from a reaction called? |
The theoretical yield |
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What does the theoretical yeild assume? |
1. All the reactants are converted into products |
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Why is the theoretical yield difficult to achieve? |
1. The reaction may not have gone to completion 2. Other reactions (side reactions) may have taken place alongside the main reactions 3. Purification of the product may result in some loss of the product |
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The amount of product obatined from a reaction is called the.... |
Actual yeild |
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Describe the relationship between the theoretical yeild and actual yeild. |
The actual yeild is lower than the theoretical yeild |
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How do you express the actual yeild of the theoretical yeild? |
By a percentage yeild, the amount in % of the threoretical yield that is actually achieved |
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What is the equation for the percentage yeild? |
actual yeild/theoretical yeild x100 |
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Describe how to calculate the percentage yeild (step by step)? |
1. Calculate the amount in moles that reacts 2. Use the equation to find the theoretical yield 3. Calculate the actual yield in moles 4. Use the molar values to calculate the percentage yield through use of the equation |
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What is the limiting reagent? |
When you use two reactants with one reactant in excess, the reactant not in excess will be completely used up first and stop the reaction - this is the limiting reagent |
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How do you work out the limiting reagent? |
By working out the number of moles of each and comparing them to the equation |
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What must calcualtions with a reactants in excess be based upon? |
The limiting reagent |
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Why must calcualtions be based upon the limiting reagent? |
Because if equal amounts of substance are allowed to react that usually do in a 2:1 ratio, the amount that is usually doubled will be used by first and the '1' will only be half used |
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What is atom economy? |
Atom economy of a chemical reaction is a measure of how well atoms have been utilised |
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Describe the properties of a reaction with a high atom economy? |
1. Produce a large proportion of desired products and few unwanted products 2. Are important for sustainability as they make the best of natural resources |
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What is atom economy solely based upon? What else does it assume? |
The balanced chemical equation It assumes a 100% yield |
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What is the eqaution for atom economy? |
Atom econ = sum of molar masses of desired products / sum of molar masses of all products |
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What does improving atom economy do? |
1. Makes individual processes more efficient 2. Preserves raw materials 3. Reduces waste |
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Describe the ideal chemical process for atom economy? |
A use would be found for all products and the atom economy would be 100% |
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Where is carbon obtained from? |
Coal |
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Where is hydrogen obtained from? |
Steam from water |
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Describe what parts atom economy dosen't shead light on? |
1. It dosen't explain the costs for the initial starting materials 2. It doesn't factor in how readily available the reactants are 3. Reactants may have a larger atom economy but poor percentage yield and efficiency depends on both factors |
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Why don't we use masses to measure gasses? What do we use instead? |
Because it is to difficult to measure the mass of a gas Gas Volumes |
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What is Avogadros law? |
Equal volumes of all gasses measured at the same temperature and same pressure will contain the same number of molecules |
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What is the symbol for molar volume? |
Vm |
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What is the molar volume? |
What volume of gas contains 6.022 x 10^23 particles |
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What space does 1 mole of gas occupy at room temperature and pressume? |
24.0 dm^3 or 24000 cm^3 |
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What is the formula for the calculation involing volume and molar volume? |
moles = volume/molar molume |
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What is the room temperature used in Avogados law? What is the pressure used? |
25 degrees celcius 1 atm (atmosphere) |
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What is the ideal gas equation used for? |
Gasses at different temperatures and pressure |
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What is the ideal gas euation? |
PV=nRT |
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What does P stand for in the ideal gas equation? What are its units? |
Pressure Pa |
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What does V stand for in the ideal gas equation? What are its units? |
Volume m^3 |
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What does the n stand for in the ideal gas equation? What are its units? |
Amount of gas Moles |
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What does R stand for in the ideal gas equation? What are its units? What is its value? |
Ideal constant Jmol^-1 K^-1 3.31 |
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What value of kilo pascals is equal to 1atm? What value of pascals is equal to 1 atm? |
101 KPa 101 x 10^3 Pa |
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What volume in m^3 is equal to 1 cm^3? What volume in m^3 is equal to 1 dm^3 |
1 x 10^-6 m^3 1 x 10^-3 m^3 |
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What does T stand for in the ideal gas equation? What are its units? |
Temperarture K (kelvin) |
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What are the assumptions the ideal gas equation is based upon? |
1. The particles have a random motion 2. The particles have no elastic collisions so energy is conserved 3. The particles have a negligible size 4. The particles have no intermolecular forces |
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How are substances made into solutions? |
By dissolving a solute into a solvent |
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What does concentration measure? |
The amount of solute in moles per dm^3 of solution |
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What unit does concenration have? |
mol dm^-3 |
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What is the formula involing concentration, moles and volume? |
Concentration = moles/volume |
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What is 1 cm^3 equal to in ml? |
1ml |
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What is 1000 cm^3 equal to in dm^3 ? What is 1000 cm^3 equal to in liters? |
1 dm^3 I litre |
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What is 1 dm^3 equal to in liters? What is 1 dm^3 equal to in ml? |
1 litre 1000 ml |
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What is the formula of an ammonium atom? What is its charge? |
NH4 +1 |
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What is the formula of an hydroxide ion? What is its charge? |
OH -1 |
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What is the formula of a nitrate ion? What is its charge? |
NO3 1- |
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What is the formula of a carbonate ion? What is its charge? |
CO3 2- |
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What is the formula of a sulphate ion? What is its charge? |
SO4 2- |
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What is the formula of a sulphite ion? What is its charge? |
SO3 2- |
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What is the formula ofa phosphate ion? What is its charge? |
PO4 3- |
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How can you work out water of cyrstallisation? |
Using MADR (same as the empirical formula) but making sure the metal is always to the ratio of 1 |
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What does monatomic mean? |
It consisits of 1 atom |
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Name 5 monatomic elements? |
1. Helium 2. Neon 3. Argon 4. Krypton 5. Radon |
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Name three giant colvalent elements? |
1. Diamond 2. Graphite 3. Silicon |
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Name one giant covalent compound? |
Silicon dioxide |
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Define the term simple molecular? |
These contain only a few atoms held together by strong covalent bonds. |
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What are diatomic molecules? |
Consisting of two atoms |
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Name 7 diatomic elemental gasses? |
1. Hydrogen 2. Nitrogen 3. Oxygen 4. Fluorine 5. Chloride 6. Bromine 7. Iodine |
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Name nine simple molecular elements? |
1. Hydrogen
2. Nitrogen 3. Oxygen 4. Fluorine 5. Chloride 6. Bromine 7. Iodine 8. Phosphorus 9. Sulfur |
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Name 7 simple molecular compounds? |
1. Carbon dioxide 2. Carbon monoxide 3. Nitrogen monoxide 4. Nitrogen dioxide 5. Sulfur dioxide 6. Sulfur trioxide 7. ammonia |
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What is the formula of a hydrogen carbonate ion?
What is its charge? |
HCO3 1- |
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What is the formula for sulfuric acid? |
H2SO4 |
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What is the formula of hydrochloric acid? |
HCl
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What is the formula of nitric acid? |
HNO3
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What is the formula of phosphoric acid? |
H3PO4
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What is silicon dioxide also known as? What is its formula? |
Silica SiO2 |
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What is the formula of a sulfide ion?
What is its charge? |
S 2- |
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What is a hydride? |
A binary (two parts) compound of hydrogen with a metal. |
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What is the forumla of silver? What is the amount of electrons given by silver? |
Ag +1 |
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What happens when you react a substance + oxygen? |
You form oxides |
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What happens when you react metal and water? |
You form a metal hydroxide + hydrogen |
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What do you form when you react a metal +acid? |
Salt + hydrogen |
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What do you form when you react a metal oxide and acid? |
Salt+ water |
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What do you form when you react a hydroxide and acid? |
Salt + water |
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What do you form when you react a carbonate +acid? |
Salt + water + carbon dioxide |
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What do you get when you react a hydrogencarbonate and acid? |
Salt + water + carbon dioxide |
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What do you get when you react ammonia and acid? |
Ammonium salt |
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What do you get when you thermally decompose a metal carbonate? |
Metal oxide + carbon dioxide |
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What is the formula of an ammonium ion? What is its charge? |
NH4 +1 |
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What is the formula of ammonia? |
NH3 |
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What is the oxidation number? What is it often called? |
The oxidation state, often called the oxidation number, is an indicator of the degree of oxidation(loss of electrons) of an atom in a chemical compound.
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What is the oxidation number of elements? |
It is always 0 |
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What is a pure element? |
A pure element is a substance consisting of only one isotope of a single element.
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What is the oxidation number of H2, O2, Na and Fe? |
They are all pure elements so 0 |
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Where is the sign of an oxidation number placed? |
Before the number |
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What is the oxidation number of Oxygen as a combined element? |
-2 |
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What is the oxidation number of hydrogen as a combined element? |
+1 |
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What is the oxidation number of Fluroine as a combined element? |
-1 |
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What is the oxidation number of an ion such as Na+ or K+ as combined elements? |
+1 |
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What is the oxidation numbers of an ion such as Mg2+ ad Ca2+ as combined elements? |
+2 |
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What is the oxidation number of ions such as Cl- or Br- as combined element? |
-1 |
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What are the special cases charges of oxidation numbers? |
1. Hydrogen in metal hydrides 2. Oxygen in peroxides 3. Oxygen bonded to Fluroine |
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What is the charge on hydrogen in a metal hydrides |
-1 |
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What is the charge of Oxygen in a peroxide? |
-1 |
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What is the charge on Oxygen bonded to Flurione? |
+2 |
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What is the rule for oxidation numbers in combined atoms? |
The sum of the oxidation numbers must equal the total charge |
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What do Roman numerals in naming show? |
The oxidation state of an element without a sign |
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What does iron(II) show? What does Iron(III) show? |
It is Fe2+ with oxidation number +2 It is Fe3+ with oxidation number +2 |
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Name some common peroxides? |
Na2O2 H2O2 BaO2 CH3COOOH |
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How does oxidation effect oxidation states? |
Oxidation involves an increase in oxidation state |
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How does reduction effect oxidation states? |
Reduction involves a decrease in oxidation state |
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What is the oxidation state of Chlorine? |
-1 |
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Why does the oxidation state of oxygen change when combined with flurione? |
Because flurione is the most electronegative element |
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Describe the actucal oxidation state of chlorine? |
There are so many different oxidation states that chlorine can have in these, that it is safer to simply remember that the chlorine doesn't have an oxidation state of -1 in them, and work out its actual oxidation state when you need it. |
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What is the oxidation state of chromium in Cr2+? |
+2 |
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What is the oxidation state of chromium in CrCl3?
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+3 |
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What is the oxidation state of chromium in the dichromate ion, Cr2O72-?
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+6 |
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What is the oxidation state of copper in CuSO4?
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+2 |
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What is the modern name of the No2- ion (nitrite)? What is the oxidation number of the oxygen? |
Nitrate(III) +3 |
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What is the modern name of the NO3- ion(nitrate)? What is the oxidation number of the oxygen? |
Nitrate(V) +5 |
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What is OILRIG? |
Oxidation is loss Reduction is gain |
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What were the terms oxidation and reduction originally applied to? |
Reactions invloving oxygen where: 1. Oxidation is the addition of oxygen 2. Reduction is the removal of oxygen |
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Describe oxidation/reduction in this reaction in terms of oxygen: CuO(s) + H2(g) --> Cu(s) +H2O(l) |
The Copper (II) has been reduced as it has lost oxygen The Hydrogen has been oxidised as it has gained oxygen |
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What are redox reactions? |
They are reactions which involve both reduction and oxidation. If one happens, so must the other - if something is reduced, something must be oxidised |
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Describe redox in terms of electrons? |
Reduction is the gain of electrons Oxidation is the loss of electrons |
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Describe redox in terms of electrons in this reaction: 2Fe(s)+3Cl2(g) --> 2FeCl3(s) |
FeCl3 contains positive and negative ions Fe^3+ and Cl^- Iron loses electrons and is oxidised 2Fe---> 2Fe^3+ 6e^- Chlorine gains electrons and is reduced 3Cl2 + 6e^- --> 6Cl^- |
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Describe redox in terms of oxidation number? |
Reduction is a decrease in oxidation number Oxidation is an increase in oxidation number |
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If Cu reacts to form a compound with an oxidation state of +2 what has it been..... |
It have lost electrons and so has been oxidised |
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If Ag reacts to form an oxidation state of +1 what has it been..... |
It has gained electrons and therefore reduced |
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What do all acids contain in their formulae? |
Hyrogen |
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What happens when an acid is dissolved in water? |
The acid releases H+ ions as protons into the water |
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What is a strong acid? |
An acid that releases all of its hydrogen atoms into solution as H+ ions and completely dissociates in aqueous solution |
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What does dissociates mean? |
Split into separate smaller atoms, ions, or molecules |
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Given an example of a strong acid? Give an example of a weak acid? |
HCl - hydrochloric acid CH3COOH - ethanoic acid |
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What is a weak acid? |
An acid that only releases a proportion of its avalibale hydrogen atoms into solution as H+ ions. It partially dissociates in aqueous solution |
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What does an equilibirium sign in a reaction dissolving an acid in an aqueous solution mean? |
That the forward reaction is not complete |
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What does a base do when it reacts with an acid? |
The base neutralises the acid to form a salt |
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What are classified as bases? |
Metal oxides, metal hydroxides, metal carbonates and ammonia |
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What is an alkali? |
It is a base that dissolves in water, releasing hydroxide ions (OH^-) into the solution |
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Define a base? |
A substance capable of reacting with an acid to form a salt and water, or of accepting or neutralizing hydrogen ions. |
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What is produced in neutralisation of an acid? |
H+ ions react with a base to form a salt and neutral water |
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What is the type of salt formed from hydrochloric acid? |
Chloride |
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What is the type of salt formed from Sulfuirc acid? |
Sulfate |
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What is the type of salt formed from nitric acid? |
Nitrate |
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What is the type of salt formed from ethanoic acid? |
Ethanoate |
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What is the type of salt prodcued from phosphoric acid? |
Phosphate |
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What is the type of salt produced from methanoic acid? |
Methanoate |
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What is a titration? |
It is a technique used to accuratley measure the volume of one solution that reacts exactly with another solution |
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What can titrations be used for? |
1. Finding the concentration of a solution 2. Identifying unknown chemicals 3. Finding the purity of a substance |
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What is checking purity of a substance important for? |
1. Quality control 2. Especially for those for human use such as medicines, food and cosmetics 3. A tiny amount of impurity could cause a great deal of harm to a patient |
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What is a standard solution? |
It is a solution of a known conentration |
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What flasks are used to make up a standard solution? |
A Volumetric flask` |
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What are the typical sizes of volumetric flasks? |
100 cm^3 250 cm^3 |
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How do you prepare a standard solution? |
1. The solid is first weighed accurtely 2. The solid is dissolved in a beaker using less distilled water than needed to fill the volumetric flask 3. The solution is transferred to a volumeric flask, the last traces of solution are rinsed in with distilled water 4. The flash is filled to the graduation line by adding distilled water dropwise untill the bottom of the meniscus lines up with the mark 5. The volumetric flask is slowly inverted to mix the solution |
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What is the line on a volumetric flask called? |
The graduation line |
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Why do you have to be careful when filling a volumetric flask to the meniscus line? |
Because if too much water is added, the solution will be too dilute and be prepared again |
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Why would results be inconsistent if the volumetric flask is not inverted during preparing a standard solution? |
Because the solution needs to be mixed |
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What tolerances are a pipette and a burette measured to? |
10cm^3 25cm^3 50 cm^3 |
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What is a burette reading read to? |
The nearest half divison with the bottom of the meniscus on a mark or between two marks. the reading always has two decimal places, the last either being a 0 or 5 |
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What is the acid-base titration procedure? |
1. Add measured volume of one solution to a conical flask using a pippette 2. Add the other solution to a burette and record the initial burette reading 3. Add a few drops of indicator to the solution in the conical flask 4. Run the solution in the burette into the solution in the conical flask, swirling it throughout to mix the two solutions 5. The indicator changes colour showing the end point of the titration. 6. Record the final burette reading 7. A quick trial tire is carried out to find the approximate tire 8. the titration is repeated accuratley, adding the solution drops wise 9. Further titrations are carried out untill two valuyes are concordant |
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What does the end point of a titration indicate? |
The volume of one solution that exactly reacts with the volume of the second solution |
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What does concordant mean? |
The values agree to within 0.10 cm^3 |
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What is it important to do when working out the mean titre? |
Use only the closest accurate values |
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What is the benifit of repeating titres untill two agree within 0.1cm^3? |
You can reject inaccurate values |
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Why do you no include all the titres in the mean titre? |
Because you would have lost the accuracy of the titration tecnnique |
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How do you carry out a titration calculation? |
1. Work out the amount in mol, or the solute in the solution for which you know both the concentration and volume 2. Use the equation to work out the amount, in mol, of the solute in the other solution 3. Work out the unknown information about the other solute in the other solution |
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What is the equation to work out the number of moles in a solution in titration calculations? |
n(X) = c x volume/1000 Divide by 1000 only when in cm^3 |
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What do you add to a metal to form a salt from ethanoic acid? |
CH3CO2
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What is an acid? |
A species that releases H+ ions in aquesous solution |
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What is a base? |
A substance capable of reacting with an acid to form a salt and water |
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In ions what it the oxidation number? |
In ions, the oxidation state is the ionic charge. |
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Why is a conical flask preffered in a titration than a beaker? |
Less chance of losing solution when stirring mixture due to angled sides of conical flask |
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What is the oxidation number for all elements? |
0 |
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What are oxidation numbers based upon? |
A set of rule that apply to all atoms and can be thought as of the number of electrons involved in bonding to a different element. |
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What does use of oxidation number help? |
It helps when writing formulae and balancing equations as a check that all electrons have been accounted for |
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What can oxidation numbers be in terms of? |
1. Oxygen 2. Electrons 3. Oxidation number |
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What is oxidation in terms of oxygen? What is reducation in terms of oxygen? |
Oxidation is addition of oxygen Reduction is removal of oxygen |
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CuO + H2 --> Cu + H2O Describe oxidation/reduction in terms of oxygen? |
The Copper oxide has lost oxygen and therefore is reduced The Hydrogen has gained oxyge and therefore has been oxidised |
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What must redox reactions contain? |
Reduction and oxidation |
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Describe redox in terms of electrons? |
Reduction is the gain of electrons Oxidation is the loss of electrons |
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Describe redox in terms of oxidation number? |
Reduction is a decrease in oxidation number Oxidation is an increase in oxidation number |
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What do dilute acids undergo redox reactions with, to produce what? |
With some metals to produce salts and hydrogen gas |
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In the deconomposition of potassium hydrogencarbonate, why would a wet crucible give an inaccurate result? |
Because the water would evaportae during heating giving a greater change of mass than actually occured |
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Why is a lid used when thermally decomposing a hydrogencarbonate using a crucible? |
To prevent loss of solid to imrpove accuracy |
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Suggest why the mass of solid remaining in a crucible was greater than expected after thermal decomposition? |
The reaction is incomplete, it didn't go to compleition and so the solid wasn't compleltley decomposed leaving a greater remenance of mass of solid |
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Why did a sealed aluminium tank explode while being used by mistake for transporting concentrated sodium hydroxide solution? |
Due to a pressure build up due to the production of hydrogen |
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Why is a 250 cm^3 flask preffered to a 250 cm^3 beaker? |
Because there is less chance of spilling solution due to the angled sides of the conical flask, when mixing, therefore making the results more accurate |
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Suggest one reason why rinsing the inside of the conical flask with deionised water can imporve the accuracry of the end point in a titration? |
The water rises any of the solution on the side of the conical flaskdown into the rest of the solution so that all of it reacts, increasing the accurary of the end point |
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Suggest why repeating a titration makes the value of the average titire more reliable? |
Because this allows for annomlolus results to be disgarded by finding two tires wiythin 0.1 cm^3 of each other |
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Suggest five ways that a titration could be imporved? |
1. Ensure bottom of meniscus is on the graduation mark 2. Wash the filter funnel (after transfer) into the flask 3. Wash the rod into the flask after use 4. Wash the beaker into the flask after transfer 5. Mix/ shake the final solution in the flask |
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Explain why the water used for rinising in a titration has no affect of the accuracy of the titre? |
Water is not a reagent, so therefore doesn't change the number of moles of the actual reagent |
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What is a normal titration? |
Alkali is in the flask, acid is in the burette |
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What is a back titration? |
Acid is in the flask, alkali is in the burette |
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Why is it important to fill the space below the tap with solution A before beginning an accurate titration? |
Because initially the space will not fill below the tap, but when the reagent runs through, this will be filled showing a produce a larger titre value than it actually was |
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Why is the volumetric flask for the standard solution slowly inverted? |
To mix the solution thoroughly, missing this could mean titration results are unlikely to be consistent |
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What happens if too much water is added to the standard solution when making it for atitration? |
The solution will be too dilute and must be prepared again |
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Describe dissociation is sulfuric acid? |
1. It behaves like a strong acid 2. The HSO4 ions formed behave as a weak acid |
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Define an acid? |
A species that releases H+ ions in aqueous solution |
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Define an alkali? |
A type of base that dissolves in water, forming hydroxide ions |
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Define amount of substance? |
The quantity whose unit of the mole is used as the means of counting any species such as atoms, ions and molecules |
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Define actual yeild? |
The amount of product obtained from a reaction |
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What is an anion? |
A negatively charged ion with more electrons than protons |
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What is the atomic (proton) number? |
The number of protons in the nucleus of an atom |
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Define Avogadro's constant? |
The number of atoms per mole of the carbon-12 isotope |
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Define a base? |
A compound that neutralises an acid to form a salt |
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Define a cation? |
A positively charged ionb with fewer electrons than protons |
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Define concentration? |
The amount of solute, in moles, dissolved in 1dm^3 of solution |
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Define the term mole? |
The amount of any substance containing as many elementary particles as there are carbon atoms in exactly 12g of the carbon-12 isotope |
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Define molecular formula? |
A formula that shows the number and type of atoms of each element present in a molcule |
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Define the term neutralisation? |
The chemical reaction in which an aicd and a base react together to produce a salt |
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Define the term oxidation? |
Loss of electrons or an increase in oxidation number |
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Define the term oxidation number? |
A measure of the number of electrons that an atom uses to bond with atoms of another element. Oxidation numbers are dervived from a set of rules |
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Define the termoxidation state? |
The oxidation number |
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Define the term oxidising agent? |
The reagent that oxidises (takes electrons from) another species |
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Define partial dissociation? |
The splitting of some of a species in solution into aqueous ions |
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Define the term redox reaction? |
A reaction involving reduction and oxidation |
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Define a reducing agent? |
A reagent that reduces (adds electrons to) another species |
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Define reduction? |
A gain of electrons or decrease in oxidation number |
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Define salt? |
The prodcut of a reaction in which the H- ions for the acid are replaced by metal or ammonium ions |
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Define spectator ions? |
Ions that are present but take no part in a chemical reaction |
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Define a standard solution? |
A solution of know concentration |
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Define titre? |
The volume added from the burette when the volume of one solution has exactly reacted with the other solution |
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Define a weak acid? |
An acid that dissociates only partially in solution |
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Define a strong acid? |
An acid that dissociates completely in solution |
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What term is used to describe a redox reaction in which an element is both oxidised and reduced? |
Disproportionation |
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Suggest how a student making a hydrated compound anhydrous could check that all the water had been removed? |
They could re-heat it and check the mass is unchanged |
