9.4. Reactivity series
A subsection of Chemistry, 0620, through 9. Metals
Listing 10 of 452 questions
When magnesium reacts with hydrochloric acid, the products are aqueous magnesium chloride and hydrogen. Mg+ 2HCl→MgCl2+ H2A student used the apparatus shown to follow the progress of this reaction. dilute hydrochloric acid magnesium Complete the diagram by putting the correct labels in the boxes. The student conducted two experiments using the same mass of magnesium in each experiment and two different concentrations of hydrochloric acid. The hydrochloric acid was in excess. All other conditions were kept constant. The student measured the volume of hydrogen produced over a period of time. The graph shows the results. time / s volume of hydrogen / cm3 0.5 mol / dm3 HCl 1.0 mol / dm3 HCl 1 12 Which concentration of hydrochloric acid gave the faster initial rate of reaction? Use the graph to explain your answer. Draw a curve on the graph on page 16 to show how the volume of hydrogen would change if a third experiment was carried out using 1.5mol/dm3 hydrochloric acid and the same mass of magnesium. Give one use of hydrogen. Explosions have occasionally been reported where tiny particles of metal dust escape into the air. Explain why metal dust can form an explosive mixture with air. [ 1 12
0620_s16_qp_32
THEORY
2016
Paper 3, Variant 2
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Period 3 contains the elements sodium to argon. This question asks about the chemistry of each of the Period 3 elements or their compounds. Sodium nitrate is a white crystalline solid. When heated it melts and the following reaction occurs. 2NaNO3→ 2NaNO2+ O2A 3.40 g sample of sodium nitrate is heated. Calculate the • number of moles of NaNO3 used, mol • number of moles of O2 formed, mol • volume of O2 formed, in dm3 (measured at r.t.p.). dm3 Magnesium reacts slowly with warm water to form a base, magnesium hydroxide. Explain what is meant by the term base. Write a chemical equation for the reaction between magnesium and warm water. Aluminium oxide is amphoteric. It is insoluble in water. Describe experiments to show that aluminium oxide is amphoteric. Silicon(oxide has a giant structure. Name the type of bonding in silicon(oxide. Give two physical properties of silicon(oxide. Calcium phosphate is used in fertilisers. The bonding in calcium phosphate is ionic. Calciumphosphate contains the phosphate ion, PO4 3–. What is ionic bonding? Deduce the formula of calciumphosphate. Sulfur tetrafluoride, SF4, can be made by combining gaseous sulfur with fluorine. S+ 2F2→ SF4The reaction is exothermic. Complete the energy level diagram for this reaction. Include an arrow which clearly shows the energy change during the reaction. energy S+ 2F2 During the reaction the amount of energy given out is 780 kJ / mol. The F–F bond energy is 160 kJ / mol. Use this information to determine the bond energy, in kJ / mol, of one S–F bond in SF4. S + F → F F F F S F F F kJ / mol Chlorine and compounds of chlorine are important in water treatment and in laboratory testing for water. Chlorine is added to water to make the water safe to drink. Explain why adding chlorine makes water safe to drink. A compound of chlorine is used in the laboratory to test for the presence of water. Name the compound of chlorine used in this test and describe the colour change seen in a positive result of this test. name of compound colour change from to Argon is an unreactive noble gas. Explain why argon is unreactive. Give one use of argon.
0620_s16_qp_41
THEORY
2016
Paper 4, Variant 1
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Zinc is extracted from an ore called zinc blende, which consists mainly of zinc sulfide, ZnS. The zinc sulfide in the ore is first converted into zinc oxide. Describe how zinc oxide is made from zinc sulfide. Write a chemical equation for the reaction in . Zinc oxide is converted into zinc. Zinc oxide and coke are fed into a furnace. Hot air is blown into the bottom of the furnace. Zinc has a melting point of 420 °C and a boiling point of 907 °C. The temperature inside the furnace is over 1000 °C. Explain how zinc oxide is converted into zinc. Your answer should include details of how the heat is produced and equations for all the reactions you describe. Explain why the zinc produced inside the furnace is a gas. State the name of the physical change for conversion of gaseous zinc into molten zinc. Rusting of steel can be prevented by coating the steel with a layer of zinc. Explain, in terms of electron transfer, why steel does not rust even if the layer of zinc is scratched so that the steel is exposed to air and water. When a sample of steel is added to dilute hydrochloric acid, an aqueous solution of iron(chloride, FeCl 2, is formed. When a sample of rust is added to dilute hydrochloric acid, an aqueous solution of iron(chloride, FeCl 3, is formed. Aqueous sodium hydroxide is added to the solutions of iron(chloride and iron(chloride. Complete the table below, showing the observations you would expect to make. iron(chloride solution iron(chloride solution aqueous sodium hydroxide Solutions of iron(chloride and iron(chloride were added to solutions of potassiumiodide and acidifiedpotassiummanganate(. The results are shown in the table. iron(chloride solution iron(chloride solution potassium iodide solution no change solution turns from colourless to brown acidified potassium manganate(solution solution turns from purple to colourless no change What types of substance cause potassium iodide solution to turn from colourless to brown? What types of substance cause acidified potassium manganate(solution to turn from purple to colourless? Which ion in iron(chloride solution causes potassium iodide solution to turn from colourless to brown? Which ion in iron(chloride solution causes acidified potassium manganate(solution to turn from purple to colourless?
0620_s16_qp_42
THEORY
2016
Paper 4, Variant 2
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Questions Discovered
452