1 Purification and Separation
2 Atomic Structure 3 Chemical Bonding 4 Mole Concept |
|
_1 Purification and Separation Techniques
1. How can pure water be obtained from a salt solution?
2. How can sodium chloride be separated from a mixture of sodium chloride and sand?
3. Water and ethanol can be separated by distillation because
4. For two substances to be separated through chromatography, what is necessary?
5. Copper (II) sulfate crystals should not be obtained by heating to dryness because
6. In the fractionating column, there are many small glass beads. Why?
7. Why is crystallization often used as a separation technique in favour over evaporation to dryness?
8. In distillation, what is the function of the condenser?
9. Which property of substance X can conclude that it is a pure substance?
10. A sample of air is passed over anhydrous copper (II) sulfate. No observation is recorded. What can be concluded?
_
1. How can pure water be obtained from a salt solution?
2. How can sodium chloride be separated from a mixture of sodium chloride and sand?
3. Water and ethanol can be separated by distillation because
4. For two substances to be separated through chromatography, what is necessary?
5. Copper (II) sulfate crystals should not be obtained by heating to dryness because
6. In the fractionating column, there are many small glass beads. Why?
7. Why is crystallization often used as a separation technique in favour over evaporation to dryness?
8. In distillation, what is the function of the condenser?
9. Which property of substance X can conclude that it is a pure substance?
10. A sample of air is passed over anhydrous copper (II) sulfate. No observation is recorded. What can be concluded?
_
_2 Atomic Structure
1. What are isotopes?
2. Which ion has the most shells that contain electrons?
3. X is a non-metallic element. Which of the following could be the electronic configuration of X?
4. Q forms a negative ion with the configuration of 2.8. Identify Q.
5. Which atom forms a positive ion of the same configuration as Neon?
6. The atomic mass of chlorine is 35.5. What does this mean?
7. Element A is a noble gas. What must be true about it?
9. What happens when water boils?
10. What is the chemical formula for gallium iodide?
1. What are isotopes?
2. Which ion has the most shells that contain electrons?
3. X is a non-metallic element. Which of the following could be the electronic configuration of X?
4. Q forms a negative ion with the configuration of 2.8. Identify Q.
5. Which atom forms a positive ion of the same configuration as Neon?
6. The atomic mass of chlorine is 35.5. What does this mean?
7. Element A is a noble gas. What must be true about it?
9. What happens when water boils?
10. What is the chemical formula for gallium iodide?
_3 Chemical Bonding
1. Which of the following substances has a macromolecular structure?
2. Which of the following substances has the best electrical conductivity?
3. Which of the following substances is likely to have the highest boiling point?
4. If element X forms the ionic compound XBr, how many valence electrons does X have?
5. If element Y forms the covalent compound YCl, how many valence electrons does Y have?
6. Which of the following statements are true about diamond and graphite?
7. Why does sodium chloride have a high melting point?
8. Explain why copper is able to conduct electricity well.
9. Explain why graphite is a covalent molecule, yet it is able to conduct electricity.
10. Why is carbon dioxide a gas but silicon dioxide a solid at room temperature and pressure?
1. Which of the following substances has a macromolecular structure?
2. Which of the following substances has the best electrical conductivity?
3. Which of the following substances is likely to have the highest boiling point?
4. If element X forms the ionic compound XBr, how many valence electrons does X have?
5. If element Y forms the covalent compound YCl, how many valence electrons does Y have?
6. Which of the following statements are true about diamond and graphite?
7. Why does sodium chloride have a high melting point?
8. Explain why copper is able to conduct electricity well.
9. Explain why graphite is a covalent molecule, yet it is able to conduct electricity.
10. Why is carbon dioxide a gas but silicon dioxide a solid at room temperature and pressure?
_4 Mole Concept
1. When excess carbon monoxide is burnt in 50 cm3 of oxygen gas, what is the volume of carbon dioxide produced?
2. What is the percentage by mass of nitrogen in 20g of ammonium nitrate?How many moles of NH4Cl react with an excess of NaOH to produce 500cm3 of gas?
3. What is the volume of sulfuric acid of concentration 2.0 mol/dm3 that is needed to react with excess zinc metal to produce 72cm3 of hydrogen gas?
4. Calculate the mass of water formed at room temperature and pressure when 2 moles of methane combusts in 3 moles of oxygen.
5. How many atoms are there in 213g of chlorine gas?How many moles of ions are present in 1.2kg iron (III) sulfate?
6. At room temperate and pressure, what is the ratio of the volume of 2g of hydrogen gas to 32g of oxygen gas?_
7. If 100 cm3 of hydrochloric acid is used to neutralize exactly 250 cm3 of a 1.0 mol/dm3 ammonium hydroxide solution, what is the concentration in g/dm3 of the hydrochloric acid solution used?
8. Find the amount of gas left over at room temperature and pressure after 24 dm3 of ethene burns in 24 dm3 of oxygen.
9. A hydrocarbon contains 81.82% by carbon and 18.18% by hydrogen. What is its empirical formula?
10. An organic compound contains 40.0% by mass of carbon and 53.3% by mass of oxygen. What is its empirical formula?
1. When excess carbon monoxide is burnt in 50 cm3 of oxygen gas, what is the volume of carbon dioxide produced?
2. What is the percentage by mass of nitrogen in 20g of ammonium nitrate?How many moles of NH4Cl react with an excess of NaOH to produce 500cm3 of gas?
3. What is the volume of sulfuric acid of concentration 2.0 mol/dm3 that is needed to react with excess zinc metal to produce 72cm3 of hydrogen gas?
4. Calculate the mass of water formed at room temperature and pressure when 2 moles of methane combusts in 3 moles of oxygen.
5. How many atoms are there in 213g of chlorine gas?How many moles of ions are present in 1.2kg iron (III) sulfate?
6. At room temperate and pressure, what is the ratio of the volume of 2g of hydrogen gas to 32g of oxygen gas?_
7. If 100 cm3 of hydrochloric acid is used to neutralize exactly 250 cm3 of a 1.0 mol/dm3 ammonium hydroxide solution, what is the concentration in g/dm3 of the hydrochloric acid solution used?
8. Find the amount of gas left over at room temperature and pressure after 24 dm3 of ethene burns in 24 dm3 of oxygen.
9. A hydrocarbon contains 81.82% by carbon and 18.18% by hydrogen. What is its empirical formula?
10. An organic compound contains 40.0% by mass of carbon and 53.3% by mass of oxygen. What is its empirical formula?
__5 Energy Changes
1. When an acid neutralizes a base, the beaker holding the solution feels warm. Why?
2. How does a catalyst work?
3. The enthalpy change of a reaction depends on..?
4. A sample of methanol (CH4) combusts completely in oxygen to produce steam and 18dm3 of carbon dioxide gas. The energy produced is found to be 5 kJ. What is the bond energy of a C-H bond?
5. Combustion reactions can never be endothermic. Do you agree?
6. The bond energy of oxygen molecules is larger than the bond energy of hydrogen molecules because..?
7. What does bond energy mean?
8. Which of the following temperature-time graphs most accurately depict an endothermic reaction?
9. Which is the correct graph showing ammonium nitrate being added to water?
10. A reaction can be said to be exothermic if..?
1. When an acid neutralizes a base, the beaker holding the solution feels warm. Why?
2. How does a catalyst work?
3. The enthalpy change of a reaction depends on..?
4. A sample of methanol (CH4) combusts completely in oxygen to produce steam and 18dm3 of carbon dioxide gas. The energy produced is found to be 5 kJ. What is the bond energy of a C-H bond?
5. Combustion reactions can never be endothermic. Do you agree?
6. The bond energy of oxygen molecules is larger than the bond energy of hydrogen molecules because..?
7. What does bond energy mean?
8. Which of the following temperature-time graphs most accurately depict an endothermic reaction?
9. Which is the correct graph showing ammonium nitrate being added to water?
10. A reaction can be said to be exothermic if..?
__6 Rate of Reaction
1. Calcium carbonate is reacted with excess aqueous hydrochloric acid to liberate carbon dioxide gas. How can the experiment be changed to liberate twice the amount of carbon dioxide gas?
2. Nitrogen gas reacts with hydrogen gas to form ammonia gas. Which change will not affect the rate of this reaction?
3. Potassium reacts with cold water to form potassium hydroxide and water. Which change will not affect the speed of the reaction?
4. What can be done to increase the volume of gas collected when excess zinc carbonate chips are added to sulfuric acid?
5. 23g of sodium is added to 1dm3 of 1 mol/dm3 sulfuric acid. What happens when the concentration of the acid is doubled?
6. Hydrogen peroxide decomposes to form water and oxygen. Which would not increase the volume of oxygen formed?
7. 10g of magnesium carbonate chips was added to an excess volume of acid. If 20g of powder had been used instead, what would not have happened?
8. If the concentration of acid were increased instead of the mass of magnesium chips, how would the reaction be affected?
9. Adding a catalyst to the decomposition of hydrogen peroxide would ..?
10. The entire reaction shown below took 10 minutes. How long did it take for half the reaction?
1. Calcium carbonate is reacted with excess aqueous hydrochloric acid to liberate carbon dioxide gas. How can the experiment be changed to liberate twice the amount of carbon dioxide gas?
2. Nitrogen gas reacts with hydrogen gas to form ammonia gas. Which change will not affect the rate of this reaction?
3. Potassium reacts with cold water to form potassium hydroxide and water. Which change will not affect the speed of the reaction?
4. What can be done to increase the volume of gas collected when excess zinc carbonate chips are added to sulfuric acid?
5. 23g of sodium is added to 1dm3 of 1 mol/dm3 sulfuric acid. What happens when the concentration of the acid is doubled?
6. Hydrogen peroxide decomposes to form water and oxygen. Which would not increase the volume of oxygen formed?
7. 10g of magnesium carbonate chips was added to an excess volume of acid. If 20g of powder had been used instead, what would not have happened?
8. If the concentration of acid were increased instead of the mass of magnesium chips, how would the reaction be affected?
9. Adding a catalyst to the decomposition of hydrogen peroxide would ..?
10. The entire reaction shown below took 10 minutes. How long did it take for half the reaction?
__7 Redox Reactions
1. When a metal atom becomes an ion, is it oxidized or reduced?
2. When a reducing agent is added to acidified potassium dichromate (VI), the solution changes from orange to green because…?
3. Potassium dichromate and potassium manganate are both oxidizing agents because…?
4. Which is true about all oxidizing and reducing agents?
5. A reducing agent is added to a purple solution X. The solution loses its colour. Identify this solution X.
6. When iron is manufactured from haematite, iron (III) oxide reacts with carbon monoxide to produce iron and carbon dioxide. Is this a redox reaction?
7. What happens when iron rusts?
8. Chlorine gas is bubbled through aqueous potassium iodide. What happens?
9. What does the (VII) in acidified potassium manganate (VII) mean?
10. The oxidation states of chromium and manganese in the oxidizing agents potassium dichromate and potassium manganate differ by..?
1. When a metal atom becomes an ion, is it oxidized or reduced?
2. When a reducing agent is added to acidified potassium dichromate (VI), the solution changes from orange to green because…?
3. Potassium dichromate and potassium manganate are both oxidizing agents because…?
4. Which is true about all oxidizing and reducing agents?
5. A reducing agent is added to a purple solution X. The solution loses its colour. Identify this solution X.
6. When iron is manufactured from haematite, iron (III) oxide reacts with carbon monoxide to produce iron and carbon dioxide. Is this a redox reaction?
7. What happens when iron rusts?
8. Chlorine gas is bubbled through aqueous potassium iodide. What happens?
9. What does the (VII) in acidified potassium manganate (VII) mean?
10. The oxidation states of chromium and manganese in the oxidizing agents potassium dichromate and potassium manganate differ by..?
__8 Acids, Bases, Salts
1. Element X burns in air to form an oxide that dissolves in both acids and alkalis. What is X likely to be?
2. When Y dissolves in HNO3 (aq), the gas produced extinguished a lighted splint with a ‘pop’ sound. What could Y be?
3. A sample of aqueous nitric acid has a pH value of 2. What could be a possible pH value after adding Potassium Iodide?
4. When Ammonium Chloride is added to solution P, gas Q is liberated. Which is likely to be P and Q?
5. Barium carbonate is added to an excess of nitric acid. What is observed?
6. What happens in the reaction between calcium hydroxide and ammonium sulphate?
7. What happens in the reaction between hydrochloric acid and copper?
8. A river is too acidic. What should be done?
9. How can sulfuric acid be distinguished from hydrochloric acid?
10. Substance Z gives off a gas that turns red litmus paper blue when aluminium powder is added. It also produces a blue ppt when NaOH is added. What is Z?
1. Element X burns in air to form an oxide that dissolves in both acids and alkalis. What is X likely to be?
2. When Y dissolves in HNO3 (aq), the gas produced extinguished a lighted splint with a ‘pop’ sound. What could Y be?
3. A sample of aqueous nitric acid has a pH value of 2. What could be a possible pH value after adding Potassium Iodide?
4. When Ammonium Chloride is added to solution P, gas Q is liberated. Which is likely to be P and Q?
5. Barium carbonate is added to an excess of nitric acid. What is observed?
6. What happens in the reaction between calcium hydroxide and ammonium sulphate?
7. What happens in the reaction between hydrochloric acid and copper?
8. A river is too acidic. What should be done?
9. How can sulfuric acid be distinguished from hydrochloric acid?
10. Substance Z gives off a gas that turns red litmus paper blue when aluminium powder is added. It also produces a blue ppt when NaOH is added. What is Z?
__9 Periodicity
1. What happens when chlorine gas is bubbled into a solution of aqueous potassium bromide?
2. Element X is found directly below potassium in the periodic table. Which of the following must be true?
3. Which of the following is true about the ions of group VII elements?
4. Why do the boiling points for elements in group I decrease down the group?
5. Why do the boiling points of elements in group VII increase down the group?
6. Going down the group, Group I elements become more reactive. Why?
7. Group VII elements become less reactive down the group. Why?
8. If elements P and Q are in the same period of the periodic table, they must have the same number of…?
9. An atom of element A gains an electron to attain the structure of a noble gas. It is the most reactive element in its group. What could element A possibly be?
10. Which element is most likely to form an oxide that can neutralize aqueous potassium hydroxide?
1. What happens when chlorine gas is bubbled into a solution of aqueous potassium bromide?
2. Element X is found directly below potassium in the periodic table. Which of the following must be true?
3. Which of the following is true about the ions of group VII elements?
4. Why do the boiling points for elements in group I decrease down the group?
5. Why do the boiling points of elements in group VII increase down the group?
6. Going down the group, Group I elements become more reactive. Why?
7. Group VII elements become less reactive down the group. Why?
8. If elements P and Q are in the same period of the periodic table, they must have the same number of…?
9. An atom of element A gains an electron to attain the structure of a noble gas. It is the most reactive element in its group. What could element A possibly be?
10. Which element is most likely to form an oxide that can neutralize aqueous potassium hydroxide?
__10 Metals
1. What happens when a piece of calcium chip is added to aqueous copper (II) sulphate?
2. Solution X contains ions of silver, potassium, calcium and lead. What happens when iron fillings are added to the solution?
3. Which metal can be obtained by heating its oxide with carbon?
4. Which metal can be obtained by heating its oxide in a stream of hydrogen gas?
5. Compound Z decomposes on heating to produce a black solid and a colourless gas. What is it?
6. 50g of iron fillings are added to a solution of copper (II) chloride. What could be the mass of iron fillings after the mixture is left to stand?
7. A piece of metal X that is stored with an iron block keeps the iron block from rusting. What is a possible identity of X?
8. Brass is an alloy. Which two metals are used to make brass?
9. Molten cryolite is used in the extraction of aluminium from aluminium oxide. What is the main function of the molten cryolite?
10. Metal A reacts with cold water and steam. Metal B reacts with steam but not with cold water. Metal C reacts with neither cold water nor steam. List the metals in order of increasing reactivity.
1. What happens when a piece of calcium chip is added to aqueous copper (II) sulphate?
2. Solution X contains ions of silver, potassium, calcium and lead. What happens when iron fillings are added to the solution?
3. Which metal can be obtained by heating its oxide with carbon?
4. Which metal can be obtained by heating its oxide in a stream of hydrogen gas?
5. Compound Z decomposes on heating to produce a black solid and a colourless gas. What is it?
6. 50g of iron fillings are added to a solution of copper (II) chloride. What could be the mass of iron fillings after the mixture is left to stand?
7. A piece of metal X that is stored with an iron block keeps the iron block from rusting. What is a possible identity of X?
8. Brass is an alloy. Which two metals are used to make brass?
9. Molten cryolite is used in the extraction of aluminium from aluminium oxide. What is the main function of the molten cryolite?
10. Metal A reacts with cold water and steam. Metal B reacts with steam but not with cold water. Metal C reacts with neither cold water nor steam. List the metals in order of increasing reactivity.
__11 Electrolysis
1. An electric current is passed through aqueous Potassium Nitrate with inert electrodes. What is formed at the anode?
2. In the electrolysis of liquid X using inert electrodes, the volume of the gas formed at the cathode is twice that of the gas formed at the anode. What could liquid X be?
3. In the electrolysis of Copper(II) Sulphate with Copper electrodes, how do the masses of the electrodes change?
4. Molten NaCl is electrolysed using platinum electrodes. What is discharged at the cathode?
5. Concentrated potassium iodide is electrolysed using carbon electrodes. What is observed?
6. Aqueous zinc chloride is electrolysed using platinum electrodes. What happens at the cathode?
7. To electroplate a necklace with silver, what must be used as the anode?
8. Which is responsible for conducting electricity in the wires in electrolysis?
9. What happens when concentrated NaCl (aq) is electrolysed using inert electrodes?
10. A simple cell is set up with zinc and metal X. The zinc electrode’s mass decreases by 13g. What happens at metal X?
1. An electric current is passed through aqueous Potassium Nitrate with inert electrodes. What is formed at the anode?
2. In the electrolysis of liquid X using inert electrodes, the volume of the gas formed at the cathode is twice that of the gas formed at the anode. What could liquid X be?
3. In the electrolysis of Copper(II) Sulphate with Copper electrodes, how do the masses of the electrodes change?
4. Molten NaCl is electrolysed using platinum electrodes. What is discharged at the cathode?
5. Concentrated potassium iodide is electrolysed using carbon electrodes. What is observed?
6. Aqueous zinc chloride is electrolysed using platinum electrodes. What happens at the cathode?
7. To electroplate a necklace with silver, what must be used as the anode?
8. Which is responsible for conducting electricity in the wires in electrolysis?
9. What happens when concentrated NaCl (aq) is electrolysed using inert electrodes?
10. A simple cell is set up with zinc and metal X. The zinc electrode’s mass decreases by 13g. What happens at metal X?
_12 Air
1. The gas that is responsible for acid rain is..?
2. Iron (II) ions in blood combine with which gas to prevent the blood from carrying oxygen?
3. Limestone is another name for calcium carbonate. What happens when acid rain reacts with limestone?
4. Which is responsible for the depletion of the ozone layer?
5. When the temperature of the water in a pond decreases, it is bad for the fish. Why?
6. Which is not true of methane?
7. Which is a source of nitrogen oxides?
8. Which is not present in dry air?
9. Ozone originates from..?
10. Which is not a gas that leaves a catalytic converter?
1. The gas that is responsible for acid rain is..?
2. Iron (II) ions in blood combine with which gas to prevent the blood from carrying oxygen?
3. Limestone is another name for calcium carbonate. What happens when acid rain reacts with limestone?
4. Which is responsible for the depletion of the ozone layer?
5. When the temperature of the water in a pond decreases, it is bad for the fish. Why?
6. Which is not true of methane?
7. Which is a source of nitrogen oxides?
8. Which is not present in dry air?
9. Ozone originates from..?
10. Which is not a gas that leaves a catalytic converter?
__13 Organic Chemistry
1. Which must be true of hydrocarbons?
2. Which must be true of all organic compounds?
3. Why is cracking important?
4. When a hydrocarbon undergoes complete combustion, what are the products formed?
5. Why do alkanes not undergo addition reactions?
6. How do isomers differ?
7. In fermentation, an air lock is used. Why?
8. In the preparation of ethanol, hydration is preferred to fermentation. Why?
9. What is the catalyst required in esterification?
10. Name a difference between nylon and terylene
1. Which must be true of hydrocarbons?
2. Which must be true of all organic compounds?
3. Why is cracking important?
4. When a hydrocarbon undergoes complete combustion, what are the products formed?
5. Why do alkanes not undergo addition reactions?
6. How do isomers differ?
7. In fermentation, an air lock is used. Why?
8. In the preparation of ethanol, hydration is preferred to fermentation. Why?
9. What is the catalyst required in esterification?
10. Name a difference between nylon and terylene