0620_w15_qp_22
A paper of Chemistry, 0620
Questions:
7
Year:
2015
Paper:
2
Variant:
2
Login to start this paper & get access to powerful tools
1
The structures of six substances are shown below. Ag Ag Ag Ag Ag Ag Ag Ag Ag Ag Ag A Fe Fe Fe Fe Fe Fe Ni Ni Ni Fe Fe Fe Xe Xe Xe Xe Xe B Na+ I– Na+ I– Na+ I– Na+ I– Na+ I– Na+ I– C D E F N O O N O O N O O F F F F F F F F Answer the following questions about these substances. Each substance may be used once, more than once or not at all. Which substance, A, B, C, D, E or F, is a simple molecular compound, is an alloy, is a compound, whose aqueous solution gives a yellow precipitate on addition of aqueous silver nitrate, is an atmospheric pollutant arising from reactions taking place in car engines, is a diatomic molecule, conducts electricity when molten but not when solid? Substance A is an element. What is meant by the term element ? Substance D oxidises water to oxygen. Complete the symbol equation for this reaction. 2F2 + 2H2O → HF +
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
9. Metals  →  9.4. Reactivity series
3. Stoichiometry  →  3.1. Formulae
Open
2
A student measured the highest temperature reached when four different fuels were burned. He used the apparatus shown below. thermometer copper can fuel clamp water spirit burner The same amount of each fuel was burned. Suggest two other things which the student should keep constant to make the experiment a fair test. 1. 2. Is burning an exothermic or an endothermic reaction? Give a reason for your answer. The table below shows the results. fuel molecular formula initial temperature / °C fi nal temperature / °C ethanol C2H6O hexane C6H14 pentane C5H12 propanol C3H8O Which fuel gave the highest temperature change? Which fuel has the highest relative molecular mass? You are not expected to do any calculations. Methane is a fuel. Draw the structure of methane showing all atoms and all bonds. Which one of the following fuels is largely methane? Tick one box. coal fuel oil gasoline natural gas Pentane and hexane belong to the same homologous series. How can you tell this from their names? Complete the following sentence about a homologous series using words from the list below. acidic alcohol compounds density different elements functional masses properties solid A homologous series is a family of similar with similar due to the presence of the same group.
11. Organic chemistry  →  11.3. Fuels
11. Organic chemistry  →  11.1. Formulae, functional groups and terminology
Open
3
The order of reactivity of zinc, magnesium, calcium and barium is shown below. zinc → magnesium → calcium → barium least reactive most reactive Equal-sized pieces of zinc, magnesium, calcium and barium are placed in water. Some observations from these reactions are shown in the table. Complete the box for barium. metal observations zinc no reaction with cold water magnesium gives a few bubbles with hot water, does not disappear calcium gives off bubbles steadily with cold water, gets smaller slowly barium Give the name of a metal in the above table which is extracted by heating with carbon. Suggest why barium cannot be extracted using carbon. Barium can be extracted by heating barium oxide with aluminium. 4BaO + 2Al → 3Ba + BaAl 2O4 How does this equation show that barium oxide gets reduced? A solution of barium hydroxide is alkaline. Describe how you would show that barium hydroxide solution is alkaline. Complete the word equation for the reaction of barium hydroxide with hydrochloric acid. barium hydroxide + hydrochloric acid → + A student used the apparatus shown below to calculate the concentration of barium hydroxide solution. hydrochloric acid barium hydroxide solution A Give the name of the piece of apparatus labelled A. The hydrochloric acid is added to the barium hydroxide solution in the fl ask until the acid is in excess. Describe how the pH of the solution changes as the acid is added. Complete the diagram below for the electrolysis of molten zinc chloride. Label the electrodes and the power source. molten zinc chloride
9. Metals  →  9.4. Reactivity series
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
Open
4
A student investigated the reaction of lumps of iron with sulfuric acid. Fe+ H2SO4→ FeSO4+ H2She used the apparatus shown below. sulfuric acid lumps of iron water Describe how this apparatus can be used to investigate the rate of this reaction. Describe how the rate of reaction would differ if smaller lumps of iron were used. All other conditions remain the same. The student investigated the effect of temperature on the reaction rate. State three factors which the student should keep the same in each experiment. 1. 2. 3. The table shows how the rate of reaction changed with temperature. temperature / °C rate of reaction in cm3 / s 2.2 4.4 8.8 17.6 Use the information in the table to describe how the rate of reaction changed with temperature. Iron(sulfate can be prepared by adding excess iron to sulfuric acid. Describe how you could obtain pure dry crystals of iron(sulfate from the reaction mixture in the conical fl ask.
6. Chemical reactions  →  6.2. Rate of reaction
Open
5
A crystal of sulfur melts when heated. Explain, using the kinetic particle theory, the differences between the arrangement and motion of the particles in sulfur crystals and liquid sulfur. Sulfur dioxide is an atmospheric pollutant. Describe how sulfur dioxide is formed and how it gets into the atmosphere. What type of oxide is sulfur dioxide? Flue gas desulfurisation removes sulfur dioxide from exhaust gases in factories. Describe the process of fl ue gas desulfurisation. Sulfur dioxide is also formed when copper is reduced by hot concentrated sulfuric acid. Complete the symbol equation for this reaction. Cu + H2SO4 → CuSO4 + SO2 + H2O Copper is a metal. Give two physical properties which are characteristic of all metals. 1. 2. The table below gives some properties of some metals that are used to make electrical cables and wires. metal strength electrical conductivity melting point / °C price $ / kg aluminium comparatively weak good 1.5 copper strong very good steel strong fairly good 2.1 silver fairly strong very good Suggest why aluminium with a steel core is used for overhead power cables. Copper is used in electrical wiring in the home rather than silver. Suggest why.
9. Metals  →  9.2. Uses of metals
9. Metals  →  9.1. Properties of metals
Open
6
Geraniol is a chemical found in rose petals. The structure of geraniol is shown below. C C H CH3 CH3 CH3 CH2 CH2 C H CH2 OH C On the structure above, put a ring around the alcohol functional group. Is geraniol a saturated or an unsaturated compound? Give a reason for your answer. Geraniol can be extracted from rose petals by steam distillation using the apparatus shown below. The geraniol is carried off in small droplets with the steam. A geraniol water heat X rose petals and water Give the name of the piece of apparatus labelled A. The vapour at point X is a mixture of geraniol and steam. Give one property of a mixture which distinguishes it from a compound. The geraniol and water are collected in the beaker. What information in the diagram above shows that geraniol is less dense than water? Geraniol can also be extracted from rose petals by grinding the petals in ethanol. Draw the structure of ethanol showing all atoms and all bonds. Complete the word equation for the complete combustion of ethanol. ethanol + oxygen → + What is the percentage by volume of oxygen in the air?
11. Organic chemistry  →  11.6. Alcohols
11. Organic chemistry  →  11.3. Fuels
Open
7
Beryllium is in Group II and Period 2 of the Periodic Table. Describe the structure of a beryllium atom. In your answer, refer to • the type and number of each subatomic particle present, • the charges on each type of subatomic particle, • the position of each type of subatomic particle in the atom. Part of the structure of beryllium chloride is shown below. Cl Cl Cl Be Cl Cl Be Cl Be Deduce the simplest formula for beryllium chloride. Beryllium carbide, Be2C, reacts with water. Beryllium hydroxide and methane are formed. Be2C + 4H2O → 2Be(OH)2 + CH4 Calculate the relative formula mass of beryllium hydroxide. Describe one adverse effect of methane on the environment.
3. Stoichiometry  →  3.1. Formulae
8. The Periodic Table  →  8.1. Arrangement of elements
Open