0620_w23_qp_41
A paper of Chemistry, 0620
Questions:
6
Year:
2023
Paper:
4
Variant:
1
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1
A list of gases is shown. ammonia carbon dioxide carbon monoxide ethene fluorine oxygen sulfur dioxide xenon Answer the following questions using only the gases from the list. Each gas may be used once, more than once or not at all. Give the name of the gas that: causes acid rain forms an alkaline solution when dissolved in water is inert is a product of photosynthesis can form a polymer is produced in the test for nitrate ions. 
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
10. Chemistry of the environment  →  10.3. Air quality and climate
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Boron and aluminium are GroupIII elements. Boron has only two naturally occurring isotopes, 10B and 11B. Complete Table2.1 to show the numbers of protons, neutrons and electrons in an atom of 11B. Table 2.1 number of protons number of neutrons number of electrons  The relative atomic mass of boron to one decimal place is 10.8. Determine the relative abundance of 10B present in boron. Give your answer as a percentage.  % Use the relative atomic mass of boron to calculate the number of atoms in 0.540 g of boron. Give your answer in standard form.  number of atoms = Aluminium is extracted from its purified ore as shown in Fig.2.1. + + + – power supply electrolyte molten aluminium anodes wires cathode Name the ore of aluminium. The electrolyte contains aluminium oxide and one other substance. Name the other substance and explain why it is used. name explanation  Write the ionic half-equation for the reaction at the cathode. Explain why the anodes need frequent replacement. State two physical properties of aluminium that make it suitable for use in overhead electrical cables.  Explain the apparent unreactivity of aluminium. Aluminium reacts with fluorine to form aluminiumfluoride, Al F3, an ionic compound. Write the symbol equation for this reaction. Complete Fig. 2.2 to show the electronic configuration of one aluminium ion and one fluoride ion. Show the charges on the ions. F Al  
9. Metals  →  9.6. Extraction of metals
9. Metals  →  9.4. Reactivity series
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Order of reactivity can be determined by displacement reactions. A student investigates the reactivities of four metals by carrying out a series of experiments. Each of the metals lead, manganese, silver and zinc are added separately to aqueous metal nitrates of the other metals. Table3.1 shows some of the results. Table 3.1 aqueous solution lead Pb manganese Mn silver Ag zinc Zn lead(nitrate ✓ manganese(nitrate silver nitrate ✓ ✓ ✓ zinc nitrate ✗ ✗ key ✓ = displacement reaction occurs ✗ = displacement reaction does not occur Complete Table3.1 and place the four metals in their order of reactivity with the most reactive first. 1 most reactive  Suggest why the metal nitrates and not the metal sulfates of these four metals are used as the aqueous solutions. Write the symbol equation for the reaction between zinc and silvernitrate. The reactivity of GroupVII elements can be investigated experimentally. A student bubbles chlorine gas into a test-tube containing aqueous potassiumbromide. Describe the colour change seen in the test-tube. from to Complete the ionic equation for this reaction. Include state symbols. + Br –→ +  The reactivity trend seen in Cl, Br and I applies to all the elements in GroupVII. Use the Periodic Table to identify the GroupVII element which cannot displace any other GroupVII elements. 
9. Metals  →  9.4. Reactivity series
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Aqueous hydrogen peroxide, H2O2, slowly forms water and oxygen at room temperature and pressure, r.t.p. This reaction is catalysed by manganese(oxide. The equation is shown. 2H2O2→ 2H2O+ O2State the test for oxygen gas. test observations  A student investigates the rate of formation of oxygen gas when manganese(oxide is added to aqueous hydrogenperoxide. The volume of oxygen gas formed is measured at regular time intervals at r.t.p. The results are plotted onto the graph in Fig.4.1. volume of oxygen gas time t2 t1 State how the graph in Fig.4.1 shows the rate of reaction at time t2, is lower than at time t1. Explain, using collision theory, why the rate of reaction at time t2 is lower than at time t1. On Fig.4.1, sketch the graph obtained when the experiment is repeated using aqueous hydrogenperoxide at a higher temperature. All other conditions remain the same. Manganese(oxide is added to 20 cm3 of aqueous hydrogenperoxide. The total volume of oxygen gas produced is 72 cm3 at r.t.p. 2H2O2→ 2H2O+ O2Calculate the concentration of the aqueous hydrogen peroxide in g / dm3 using the following steps. ● Calculate the number of moles of oxygen gas produced.  mol ● Determine the number of moles of hydrogen peroxide which reacts.  mol ● Calculate the concentration of aqueous hydrogenperoxide in mol / dm3.  mol / dm3 ● Calculate the concentration of aqueous hydrogen peroxide in g / dm3.  g / dm3  Suggest the identity of one other metal oxide which also catalyses this reaction. 
6. Chemical reactions  →  6.2. Rate of reaction
6. Chemical reactions  →  6.4. Redox
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Methane reacts with steam to produce hydrogen gas. CH4+ H2OCO+ 3H2∆H = +200 kJ / mol The reaction takes place at 1000 °C and 100 kPa pressure. The reaction is reversible and reaches an equilibrium in a closed system. State two features of an equilibrium.  State and explain, in terms of equilibrium, what happens to the concentration of hydrogen when: the pressure is increased the temperature is increased a catalyst is used. Methane is a greenhouse gas which contributes to global warming. Name a greenhouse gas found in clean, dry air. Explain, in terms of thermal energy, how greenhouse gases cause global warming. 
6. Chemical reactions  →  6.3. Reversible reactions and equilibrium
10. Chemistry of the environment  →  10.3. Air quality and climate
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Ethanol is manufactured by two methods: method 1 fermentation of aqueous glucose method 2 catalytic addition of steam to an alkene. Method1 takes place at room temperature and pressure. State two other conditions needed in method1.  State the typical temperature and pressure used in method2. temperature °C pressure kPa  Name the alkene used in method2. State why the reaction in method2 is referred to as an addition reaction. The catalyst in method2 is phosphoricacid, H3PO4. Dilute phosphoricacid is a weak acid which contains phosphate ions, PO4 3–. State what is meant by the term acid. State the meaning of weak in the term weak acid. Determine the oxidation number of phosphorus in the PO4 3– ion. Show your working.  oxidation number = Give one advantage of each method of production of ethanol. method 1 method 2  Ethanol can be converted to ethanoicacid by reacting it with an acidified oxidising agent. Name the acidified oxidising agent. State, in terms of redox, what type of reagent ethanol is in this reaction. Ethanoicacid reacts with calcium to form a salt and one other product. Name the salt. Write the formula of the salt. Identify the other product. 
11. Organic chemistry  →  11.6. Alcohols
11. Organic chemistry  →  11.7. Carboxylic acids
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