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56 Cards in this Set
- Front
- Back
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Chemistry |
C3 |
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Why are there gaps in the periodic table? |
For undiscovered elements |
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Why did scientists support Mendeleev's predictions? |
Because he predicted the properties of gallium and it was discovered in 1875 |
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Which elements occur naturally on earth? |
1 to 92 |
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How are elements above 93 made? |
In nuclear reactors |
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What are transition metals? |
Typical metals |
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What can transition metals do? |
Alter their electron arrangement to form different ions, for example Fe2+ AND Fe3+ |
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What are transition metals useful as? |
Catalysts |
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What are group seven elements known as? |
Halogens |
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Why are smaller halogens more reactive than larger ones? |
Because the attraction from the nucleus is bigger, so electrons are attracted to it more easily |
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What happens to hydrogen chloride gas when it is dissolved in water? |
It becomes hydrogen and chlorine atoms which forms hydrochloric acid (because of the hydrogen ions: H+) |
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What causes permanent hard water? |
Dissolved calcium/ magnesium sulfate, nitrate, or chloride |
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What causes temporary hard water? |
Calcium/ magnesium hydrocarbonate |
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How can temporary hardness be removed? |
By boiling water, which changes the hydrogen carbonate to carbonate ions and releases carbon dioxide. |
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How can permanent hardness be removed? |
By adding sodium carbonate or passing it through an ion exchange column |
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How does an ion exchange column work? |
It contains sodium or hydrogen ions which replace the calcium or magnesium in the water |
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What does hard water and soap produce? |
Insoluble scum |
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What precipitate is achieved by adding sodium carbonate? |
Calcium or magnesium carbonate |
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How does a water filter work? |
Carbon absorbs impurities. Ion exchange resins swap metal ions for hydrogen. Silver nanoparticles kill microbes in the water. |
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How does distillation work? |
Impure water is boiled, then condensed. It is expensive because boiling the water requires so much energy. |
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How can the energy in food be measured? |
By burning the food and measuring the temperature rise it causes in water. |
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How are calories converted to joules? |
By multiplying calories by 4.2 |
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What happens in exothermic reactions? |
Less energy is needed to make the bonds in the products than to break the bonds in the reactants, so there is "spare" energy. This is given off to the surroundings as heat. |
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What happens in endothermic reactions? |
More energy is needed to make the bonds in the products than to break the bonds in the reactants, so the reaction requires energy. This is taken from the surroundings, therefore cooling them down. |
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In a methane molecule (carbon bonds to four hydrogens) which bond is the hardest to break? |
The last one, the energy given for each bond is an average. |
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How can hydrogen gas be produced? |
By electrolysing water |
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Is using hydrogen as a fuel more efficient in a normal car, or in the battery of an electric car? |
Electric car! (60% efficient) Normal car is only 20% efficient |
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What are two advantages of hydrogen fuel? |
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What are three disadvantages of hydrogen fuel? |
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In a fuel cell, where are oxygen and hydrogen gases fed to? |
Oxygen is fed to a cathode
Hydrogen is fed to an anode . |
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What catalyst is used to remove the electrons from the hydrogen? |
Platinum |
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Where do the hydrogen electrons go after being removed from the hydrogen? |
Round the circuit to react with the hydrogen and oxygen to produce water |
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What can barium sulfate be used for? |
It can be put through the body as it is insoluble, and then shows up on x-rays of soft tissue in intestines. |
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How many particles are in a mole? |
Avogadro's number (6.02 x10 ^13) |
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What is concentration measured in? |
moles/ dm^3 |
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In titrations, what goes in the beaker? |
Acid with known concentration plus indicator. |
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In a titration, what goes in the burette? |
Alkali solution |
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In a reversible reaction, what is equilibrium? |
When a reaction is going both ways at the same speed |
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How can the dynamic equilibrium be shifted in one direction? |
By changing conditions such as temperature |
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How can the reaction to produce ammonia be increased in the forward direction? |
By increasing the pressure |
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How is ammonia made? |
The Haber process! |
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Why is ammonia production more efficient at lower temperatures? |
Because it is an exothermic reaction, if the surroundings are heated then it will cause the reaction to happen in the opposite direction. |
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What happens to unreacted nitrogen and hydrogen in the haber process? |
It is recycled |
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What happens in the Haber process? |
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Describe the efficiency of the haber process |
A small amount of ammonia is produced at a very fast rate. This is more efficient than a higher amount at a slower rate. |
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What is formed when alcohols dissolve in water? |
Neutral solutions (molecules do not form ions) |
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What do alcohols produce when reacted with sodium? |
Sodium (prefix)oate and hydrogen. Eg, ethanol produces sodium ethanoate. |
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What is produced when an alcohol is reacted with oxygen? |
Carbon dioxide |
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What is vinegar made of? |
Ethanoic acid and water |
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What homologous series of compounds is ethanoic acid part of? |
Carboxylic acids |
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What is the functional group of the carboxylic acids? |
-COOH |
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What do ethanoic acids and water produce? |
Hydrogen ions, so are acidic. (Becomes COO- and H+) |
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What do carboxylic acids and metal carbonates produce?
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Carbon dioxide, water, and metal salt of the acid |
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What do alcohols and carboxylic acids produce? |
Smelly compounds known as esters. |
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What sort of acid is a carboxylic acid when it is dissolved in water? |
Weak ass acid |
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Top lad |
Gonna slay this chemistry test |
