0620_s17_qp_41
A paper of Chemistry, 0620
Questions:
6
Year:
2017
Paper:
4
Variant:
1
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1
This question is about subatomic particles. Define the terms proton number, nucleon number. Why is the 1H 1 hydrogen atom the only atom to have an identical proton number and nucleon number? Complete the table to show the number of protons, neutrons and electrons in the atoms and ions given. number of protons number of neutrons number of electrons 19F 26Mg 31P3– 87Sr2+ Write the formula of the compound formed from fluorine and magnesium. Write the formula of the compound formed from Sr2+ and P3–.
2. Atoms, elements and compounds  →  2.2. Atomic structure and the Periodic Table
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2
Some oxides of some elements are listed. CO CO2 Na2O MgO Al 2O3 SiO2 P4O10 SO2 Cl 2O7 Cr2O3 Answer the following questions using only oxides from the list. Each oxide may be used once, more than once or not at all. Give the formula of an oxide which is the main cause of acid rain, which would give a solution of pH 14 when added to water, which is coloured, which is the major impurity in iron ore, which is amphoteric, which is neutral. Amphoteric oxides and neutral oxides are different from each other. What is meant by the term amphoteric oxide? What is meant by the term neutral oxide?
7. Acids, bases and salts  →  7.2. Oxides
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Magnesium sulfate and lead(sulfate are examples of salts. A student prepared magnesium sulfate crystals starting from magnesium carbonate. The student carried out the experiment in four steps. step 1 The student added excess magnesium carbonate to a small volume of dilute sulfuric acid until no more magnesium carbonate would react. step 2 The student filtered the mixture. step 3 The student heated the filtrate obtained from step 2 until it was saturated. step 4 The student allowed the hot filtrate to cool to room temperature and then removed the crystals which formed. How did the student know when the reaction had finished in step 1? Name the residue in step 2. A saturated solution forms in step 3. What is a saturated solution? Explain why magnesium sulfate crystals form during step 4. Magnesium sulfate crystals are hydrated. Another student heated some hydrated magnesiumsulfate crystals in a crucible and obtained the following results. mass of hydrated magnesium sulfate crystals = 4.92 g mass of water removed = 2.52 g Calculate the number of moles of water removed. moles of water = mol Calculate the number of moles of anhydrous magnesium sulfate remaining in the crucible. The Mr of anhydrous magnesium sulfate is 120. moles of anhydrous magnesium sulfate = mol Calculate the ratio of moles of anhydrous magnesium sulfate : moles of water. Give your answer as whole numbers. ratio = : Suggest the formula of hydrated magnesium sulfate crystals. formula of hydrated magnesium sulfate crystals = Lead(sulfate, PbSO4, is insoluble. Describe how you would prepare a pure dry sample of lead(sulfate crystals starting from solutions of lead(nitrate and sodium sulfate. Include a series of key steps in your answer. Write the ionic equation for the reaction which takes place between solutions of lead(nitrate and sodium sulfate. Include state symbols.
9. Metals  →  9.4. Reactivity series
7. Acids, bases and salts  →  7.3. Preparation of salts
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Zinc is a very important metal. Zinc is extracted from its ore, zinc blende. Zinc blende contains zinc sulfide, ZnS. Zinc sulfide is converted to zinc oxide in an industrial process. Describe how zinc sulfide is converted to zinc oxide in this industrial process. Write the chemical equation for this reaction. Zinc oxide is then reduced in a furnace. Name the substance added to the furnace to reduce the zinc oxide. Describe how the pure zinc is removed from the furnace and collected. When rods of zinc and copper are placed into dilute sulfuric acid as shown, electricity is generated. copper rod dilute sulfuric acid zinc rod bulb Write the ionic half-equation for the reaction occurring at the zinc rod. Write the ionic half-equation for the reaction occurring at the copper rod. The copper rod was replaced by an iron rod. Suggest the change, if any, in the intensity of the light emitted from the bulb and give a reason for your answer. change reason
9. Metals  →  9.4. Reactivity series
4. Electrochemistry  →  4.1. Electrolysis
9. Metals  →  9.5. Corrosion of metals
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5
When barium carbonate is added to dilute hydrochloric acid, carbon dioxide gas is formed. A student carried out an experiment to measure the volume of gas formed as a reaction proceeds. The student added a small mass of powdered barium carbonate to an excess of 0.1 mol / dm3 hydrochloric acid. A graph of the results was drawn. The graph is shown. volume of gas / cm3 time / s Name the two pieces of apparatus needed to take the measurements shown on the graph. On the axes below, sketch a graph to show how the rate of reaction changes as the reaction proceeds. Assume the initial rate of reaction is represented by the point at X. time / s rate of reaction X The total volume of gas collected was 180 cm3 at room temperature and pressure. Calculate the mass, in grams, of barium carbonate used. BaCO3 + 2HCl BaCl 2 + H2O + CO2 mass of barium carbonate = g The original graph has been drawn again. On the grid, draw the graph expected if the same mass of barium carbonate is added as large lumps instead of as a powder. All other conditions are the same as in the original experiment. Explain why your graph is different from the original graph. volume of gas / cm3 time / s The original graph has been drawn again. On the grid, draw the graph expected if the concentration of dilute hydrochloric acid is changed from 0.1 mol / dm3 to 0.2 mol / dm3. All other conditions are the same as in the original experiment. Explain, in terms of particles, why your graph is different from the original graph. volume of gas / cm3 time / s The experiment is changed and the mass of powdered barium carbonate is doubled. All other conditions are the same as in the original experiment. The acid is still in excess. Deduce the volume of gas formed at room temperature and pressure, in cm3, in this experiment. volume of gas = cm3
6. Chemical reactions  →  6.2. Rate of reaction
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6
The alkenes and alkanes are both examples of homologous series which are hydrocarbons. What is meant by the term hydrocarbon? Give three characteristics of an homologous series. Name and draw the structure of the second member of the alkene homologous series. Show all of the atoms and all of the bonds. name structure Alcohols can be made from alkenes. Name the reagent and conditions needed to convert an alkene into an alcohol. The alcohol butanol, CH3CH2CH2CH2OH, can be converted into a carboxylic acid with four carbon atoms. Name the carboxylic acid formed from butanol and draw its structure. Show all of the atoms and all of the bonds. name structure Ethanoic acid can be formed from ethanol by fermentation. It can also be formed by the addition of a suitable chemical reagent. Name the reagent needed to convert ethanol into ethanoic acid. State the type of chemical change which occurs when ethanol is converted into ethanoicacid. Describe how a student could prepare the ester methyl ethanoate in a school laboratory. In your description give ● the names of the two starting organic chemicals, ● the essential reaction conditions needed, ● a chemical equation for the reaction.
11. Organic chemistry  →  11.2. Naming organic compounds
11. Organic chemistry  →  11.5. Alkenes
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