5070_w23_qp_22
A paper of Chemistry, 5070
Questions:
9
Year:
2023
Paper:
2
Variant:
2
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1
Choose from the list of compounds to answer these questions. ammonia ethanol glucose magnesium chloride magnesium oxide methane nitrogen dioxide phosphorus(chloride polysodium bromide water Each compound may be used once, more than once or not at all. Identify the compound that: is a waste gas from digestion in animals turns blue cobalt(chloride pink reacts with ethene above 100 °C to produce ethanol is a product of photosynthesis contains an anion with a charge of –2.
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
10. Chemistry of the environment  →  10.1. Water
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2
This question is about metals. Chromium is a transition element. Sodium is an element in Group I of the Periodic Table. State two physical properties of chromium that are different to those of sodium. Deduce the number of protons and neutrons in the chromium atom shown. 24 Cr number of protons number of neutrons Chromium(oxide, Cr2O3, reacts with carbon and chlorine to produce chromium(chloride, CrCl3, and carbon monoxide. Construct the symbol equation for this reaction. Complete the diagram in to show the electronic configuration of a sodium ion. Include the charge on the ion. Na Table 2.1 shows the observations made when four different metals are heated in oxygen. Table 2.1 metal observations lanthanum forms a layer of oxide rapidly on the surface but does not burn mercury does not form a layer of oxide on the surface nickel forms a layer of oxide slowly on the surface but does not burn sodium burns rapidly Put the four metals in order of their reactivity. Put the least reactive metal first. least reactive most reactive Aluminium is used in food containers and overhead electrical cables because it is resistant to corrosion. Explain why aluminium is resistant to corrosion. State two other reasons why aluminium is used in overhead electrical cables.
9. Metals  →  9.2. Uses of metals
9. Metals  →  9.4. Reactivity series
9. Metals  →  9.1. Properties of metals
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3
A student investigates the reaction of large pieces of calcium carbonate with dilute hydrochloric acid at 25 °C. The hydrochloric acid is in excess. Complete the equation for this reaction by adding state symbols. CaCO3( ) + 2HCl ( ) CaCl2+ H2O( ) + CO2 shows the volume of carbon dioxide gas released as the reaction proceeds. time / s volume of carbon dioxide / cm3 Deduce the volume of carbon dioxide gas released after 40 seconds. volume cm3 The student repeats the experiment using the same mass of smaller pieces of calcium carbonate. All other conditions stay the same. Draw a line on the grid in to show how the volume of carbon dioxide changes when smaller pieces of calcium carbonate are used. The student repeats the experiment at 20 °C. All other conditions stay the same. Describe and explain, using collision theory, how the rate of reaction differs when a temperature of 20 °C is used. A sample of carbon dioxide is put into a gas syringe. The end of the gas syringe is then blocked so that no gas can escape. Explain, using kinetic particle theory, why increasing the pressure in the gas syringe decreases the volume of gas when the temperature stays the same.
1. States of matter  →  1.1. Solids, liquids and gases
6. Chemical reactions  →  6.2. Rate of reaction
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4
Concentrated aqueous magnesium iodide is electrolysed using graphite electrodes. Predict the product at each electrode. anode cathode Molten magnesium iodide is electrolysed using graphite electrodes. Construct the ionic half-equation for the reaction at each electrode when molten magnesium iodide is electrolysed. anode cathode Describe a test for aqueous iodide ions. Include the observations for a positive result. test observations Iodide ions reduce manganese(oxide, MnO2, to Mn2+ ions. 2I– + MnO2 + 4H+ Mn2+ + I2 + 2H2O Explain, in terms of movement of electrons, how iodide ions act as a reducing agent in this reaction. State the name of the type of reaction that involves simultaneous oxidation and reduction. Phosphorus(iodide is produced when phosphorus reacts with iodine. Complete to show the dot-and-cross diagram for a molecule of phosphorus(iodide. Show only the outer shell electrons. P I I I
4. Electrochemistry  →  4.1. Electrolysis
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shows the displayed formula of compound A. H H H H H H H C C C C O H On , draw a circle around the functional group that reacts with aqueous bromine. Describe the colour change when excess compound A is added to a few drops of aqueous bromine in a test tube. colour of aqueous bromine colour after addition of compound A Deduce the molecular formula of compound A. Compound A is a liquid at room temperature. Describe the motion and separation of the particles in a liquid. motion separation shows the structure of compound B. H H H H H H H C C C C H Compound B is polymerised. Draw two repeat units of the polymer formed when compound B is polymerised. Describe two environmental challenges caused by the disposal of plastics.
11. Organic chemistry  →  11.5. Alkenes
11. Organic chemistry  →  11.8. Polymers
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6
Steam reacts with carbon to produce carbon monoxide and hydrogen. steam + carbon carbon monoxide + hydrogen The forward reaction is endothermic. Explain, in terms of bond making and bond breaking, why this reaction is endothermic. The transfer of thermal energy in a chemical reaction is called the enthalpy change. Write the symbol for an enthalpy change. Include the sign for an endothermic enthalpy change. Carbon monoxide, water and carbon dioxide are formed during the incomplete combustion of carbon-containing fuels. Name one other substance formed during the incomplete combustion of carbon-containing fuels. State one adverse effect of carbon monoxide. Hydrogen is used in a hydrogen-oxygen fuel cell. Describe two advantages of a hydrogen-oxygen fuel cell compared with a gasoline / petrol engine.
5. Chemical energetics  →  5.1. Exothermic and endothermic reactions
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7
Dilute hydrochloric acid reacts with aqueous sodium carbonate. 2HCl + Na2CO3 2NaCl + H2O + CO2 A student titrates 20.0 cm3 of 0.0250 mol / dm3 aqueous sodium carbonate with dilute hydrochloric acid using methyl orange as an indicator. A volume of 15.5 cm3 of dilute hydrochloric acid reacts exactly with the 0.0250 mol / dm3 aqueous sodium carbonate. Calculate the concentration, in mol / dm3, of the dilute hydrochloric acid. concentration of dilute hydrochloric acid mol / dm3 State the colour of methyl orange in alkaline solution. Write the formula of the ion present in aqueous solutions of alkalis. Calculate the volume, measured at r.t.p., of carbon dioxide produced, in cm3, when 2.65 g of sodium carbonate reacts with excess hydrochloric acid. 2HCl + Na2CO3 2NaCl + H2O + CO2 volume of carbon dioxide cm3 Hydrochloric acid is a strong acid. Define the term strong in the phrase strong acid. Oxides of nitrogen contribute to acid rain. State one other adverse effect of oxides of nitrogen. Oxides of nitrogen are removed from car exhausts by catalytic converters. Complete the symbol equation for the reaction that occurs in catalytic converters. 2CO + 2NO +
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
7. Acids, bases and salts  →  7.1. The characteristic properties of acids and bases
9. Metals  →  9.4. Reactivity series
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8
The equation for the reaction of carbon monoxide with hydrogen at a high temperature in a closed container is shown. CO+ 2H2CH3OHmethanol The forward reaction is exothermic. Predict and explain the effect, if any, on the position of equilibrium when the pressure is increased and the temperature remains constant. Predict and explain the effect, if any, on the position of equilibrium when the temperature is increased and the pressure remains constant. Methanol reacts with ethanoic acid, CH3COOH, to produce an ester. Name the ester and draw its displayed formula. name displayed formula Methanol is a member of the alcohol homologous series. Describe two general characteristics of a homologous series.
11. Organic chemistry  →  11.1. Formulae, functional groups and terminology
6. Chemical reactions  →  6.3. Reversible reactions and equilibrium
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9
Table 9.1 shows the melting points and relative electrical conductivities of three elements. Table 9.1 calcium carbon iodine melting point / °C relative electrical conductivity of solid good poor poor Use ideas about structure and bonding to explain: the difference in the melting points of diamond and iodine the difference in the electrical conductivities of calcium and iodine. Diamond and graphite are different forms of carbon. Explain, in terms of its structure, why graphite is a lubricant. A compound of sodium, iodine and oxygen contains 11.62% sodium, 64.14% iodine and 24.24% oxygen by mass. Deduce the empirical formula of this compound. empirical formula
2. Atoms, elements and compounds  →  2.4. Ion and ionic bonds
2. Atoms, elements and compounds  →  2.5. Simple molecules and covalent bonds
2. Atoms, elements and compounds  →  2.6. Giant covalent structures
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