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54 Cards in this Set
- Front
- Back
what does your stomach produce to kill bacteria? |
hydrochloric acid |
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what does hydrochloric in the stomach prevent? |
food poisioning |
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how is the food in your stomach broken down? |
the food is digested (broken down) by digestive enzymes which needs acidic conditions to work properly |
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what happens when your body produces too much acid? |
indigestion |
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what happens if the acid escapes? |
the acid will escape from the top of the stomach which causes pain in the tube leading to the mouth which is known as heartburn |
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what can neutralise acids and why? |
medicines such as antacids neutralise excess acid because they contain bases (substances that reacts with acid) |
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what is the formula for the neutralisation of acids? |
acid + base (arrow) salt + water |
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what is an alkali? |
some bases are soluble and a base dissolved in water is an alkali |
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what is the formula if an indigestion tablet reacts with magnesium hydroxide? |
magnesium hydroxide + hydrochloric acid (Arrow) magnesium chloride + water |
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what is the symbol equation for an indigestion tablet reacting with magnesium hydroxide? |
Mg(OH)2 + HCL 2 (arrow) 2MgCl2 + 2H2O |
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what is the word and symbol equation if sodium hydroxide reacts with an indigestion tablet? |
sodium hydroxide + hydrochloric acid (arrow) sodium chloride + water Na(OH)2 + 2HCL (arrow) NaCl2 + 2H2O |
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what is the word and symbol equation if copper oxide reacts with an indigestion tablet? |
copper oxide + hydrochloric acid (Arrow) copper chloride + water CuO + 2HCL2 (arrow) CuCl + 2H20 |
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What is the word and symbol equation if potassium hydroxide reacts with sulphuric acid? |
potassium hydroxide + sulphuric acid ( arrow) potassium sulphate + water |
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what will the reactions of substances reacting with indigestion produce? |
a colourless solution |
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what two things do we have to observe for the reaction of substances reacting with indigestion tablets? |
if there is a rise in temperature and if the pH of the reaction mixture changes and you will observe the same things for metal oxides |
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what is produced if an antacid contains carbonate? |
carbon dioxide will be produced |
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give the word and symbol equation for hydrochloric acid reacting with calcium carbonate? |
hydrochloric acid + calcium carbonate (Arrow) calcium chloride + water + carbon dioxide CaCO3 + 2HCl2 (arrow) CaCl2 + H2O + CO2 |
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are most metal carbonates soluble? |
no |
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what do we get when an antacid reacts with carbonates? |
acid + metal carbonate (arrow) salt + water + carbon dioxide |
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what will you observe when antacids reacts with a carbonate? |
you will observe bubbles of gas being given off and you can show the gas is carbon dioxide by bubbling it through limewater which turns a cloudy white when it reacts with carbon dioxide |
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if I react calcium carbonate with hydrochloric what will be my three products? |
calcium chloride + water + carbon dioxide |
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how can we find out is something is an acid or an alkali? |
we can use an indicator to find out if it is an acid or an alkaline. the pH scale shows colours of the universal indicator. litmus paper is an indicator. the blue litmus paper will turn red under acidic conditions and the red litmus paper will turn blue under alkaline solutions but the litmus paper must be damp. |
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how are dangers shown when associated with substances? |
we have symbols |
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if an acid or alkali is spilt how can we make this safe? |
it can be made safe by diluting it with water and by neutralising the acid |
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what are the conditions to neutralise acid? |
must be a: - metal oxide - metal hydroxide - metal carbonate |
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what is the word equation for neutralising an acid? |
acid + metal oxide (Arrow) salt + water |
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what is the word equation when neutralising sulphuric with an metal oxide? |
sulphuric acid + copper oxide (Arrow) copper sulphate and water |
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what is the word equation when neutralising nitric acid with a metal hydroxide? |
nitric acid + sodium hydroxide (Arrow) sodium nitrate + water |
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what is the word equation when neutralising hydrochloric acid with a metal carbonate? |
hydrochloric acid + copper carbonate (arrow) copper chloride + water + carbon dioxide |
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what do sulphuric acids produce? |
sulfate salts |
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what do nitric acids produce? |
nitrate salts |
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what do hydrochloric acids produce? |
chloride salts |
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how are compounds decomposed to form new compounds? |
1. heat - thermal decomposition 2. electricity- electrolysis (compounds are decomposed by electrolysis are called electrolytes) |
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how is chlorine gas produced as an electrode in sea water? |
sea water contains dissolves substances and the common one is sodium chloride. if a direct current passes through the sea water chlorine gas is produced as one of my electrodes |
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what is the test for chlorine? |
1. hold damp blue litmus paper at the mouth of the tube in chlorine water 2. if the gas is chlorine the red litmus paper will be bleached into white litmus paper 3. any acidic substance will turn blue litmus paper red |
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what are the uses of chlorine? |
chlorine is a yellow/green toxic gas but is used in swimming pools to keep the water free from bacteria, this kills microorganisms in the water and is used for cleaning products and for the manufacture of plastics |
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what are the disadvantages of using chlorine? |
this is harmful to living things but reacts with coloured substances converting them to colourless products and is used in paper making |
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what are the risks of chlorine? |
- gases can accidentally leak from a chemical factory or a tanker carrying this gas may be involved in an accident - chlorine is a toxic gas and if it leaks many people can be badly injured or killed |
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how are ionic substances broken down into simper substances? |
broken down into simpler substances using electrolysis |
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what is formed through electrolysis? |
metals and gases are formed at the electrodes when an electric current is passed through them |
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describe the process of electrolysis: |
1. electrolysis breaks down compounds using electrical energy 2. the electricity comes from direct currents eg. battery 3. requires liquid to conduct electricity called the electrolyte 4. electricity is applied to the electrolyte by two electrodes 5.electrolyte contains compounds which are broken down into its components part 6. component parts are released as atoms or molecules often as a gas |
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what do the ionic substances need for electrolysis? |
the ions must be free to move and ions are only free to move when an ionic substance is dissolved in water or molten (melted) |
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describe the process of electrolysis through the positive and negative ions |
1. positively charged ions move to the negative electrode during electrolysis and receive electrons and are reduced 2. negatively charged ions move to the positive electrodes during electrolysis so they lose electrons and are oxidised |
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what does the electrolysis of dilute hydrochloric acid produce? |
produces hydrogen and chlorine gas which can also be produced by the electrolysis of sea water and if a direct current is passed through water, hydrogen and oxygen are given off at the electrodes |
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describe the electrolysis of hydrochloric acid: |
1. electrolyte is a dilute solution of hydrochloric acid 2. applying a direct current to the electrolyte causes the HCl to decompose into hydrogen and chlorine gas 3. the gases bubble through the solution and can be collected at the electrodes. |
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describe the test for hydrogen
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2. if the test tube contains hydrogen mixed with air it will explode with a squeaky pop |
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describe the test for oxygen
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1. light a splint and then blow the flame out 2. end of the light splint should be glowing 3. put the glowing splint in the mouth of the test tube. if the gas is oxygen the glowing splint will then relight |
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describe the test for chlorine
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chlorine bleaches damp litmus paper turning it red |
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what can hydrogen be used for?
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used for rocket fuel and pure hydrogen can be obtained from electrolysis but it is flammable
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what can chlorine be used for? |
to treat water supplies and kill any microorganisms, manufacture of bleach products, used to make a polymer (PVC), but it is a toxic gas |
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what can oxygen be used for?
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used for patients in hospitals who need extra oxygen or space crafts carry cylinders of oxygen or make pure oxygen by electrolysis |
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what is sodium hydroxide used for?
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turns red litmus paper blue but it is corrosive
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what is brine?
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a concentrated sodium chloride solution |
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what happens when an electric current passes through brine? |
if an electric current passes through brine then hydrogen gas forms as the negative electrode and chlorine gas forms as the positive electrode and a solution of sodium hydroxide forms
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