0620_w19_qp_31
A paper of Chemistry, 0620
Questions:
7
Year:
2019
Paper:
3
Variant:
1
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1
This question is about solids, liquids and gases. The list gives the names of nine substances which are solids at room temperature. a ceramic aluminium anhydrous cobalt(chloride anhydrous copper(sulfate calcium oxide graphite iodine iron sodium Answer the following questions about these substances. Each substance may be used once, more than once or not at all. State which substance: turns pink when water is added to it is a non-metal which is used as a lubricant is used to neutralise acidic industrial waste is extracted from bauxite is used as an electrical insulator. Some changes of state of sodium are shown. solid sodium liquid sodium sodium gas A freezing B evaporation State the names of the changes of state represented by A and B. A B  Use the kinetic particle model to describe the arrangement and separation of the particles in: solid sodium liquid sodium.  
1. States of matter  →  1.1. Solids, liquids and gases
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Biogas is made by fermenting animal and vegetable waste. The table shows the percentage composition of the gases present in a sample of biogas. substance present percentage present in biogas carbon dioxide 28.5 hydrogen 1.0 methane 62.0 nitrogen water vapour 2.4 other substances 0.1 total 100.0 Deduce the percentage of nitrogen present in this sample of biogas. Balance the chemical equation for the complete combustion of methane. CH4 + O2 CO2 + H2O Which one of these compounds belongs to the same homologous series as methane? Draw a circle around the correct answer. methanoic acid methanol propane propanol propene Methane is present in the refinery gas fraction produced by the fractional distillation of petroleum. Match the fractions on the left with their uses on the right. The first one has been done for you. fraction use refinery gas making roads fuel oil fraction making chemicals bitumen fuel for heating and cooking naphtha fraction fuel for ships  Draw a dot-and-cross diagram to show the electron arrangement in a molecule of hydrogen.  State one use of hydrogen. The biogas contains a small amount of compound C. The structure of compound C is shown. H H H C C H S H H O O H N C On the structure shown, draw a circle around the carboxylic acid functional group. How many different types of atoms are present in compoundC? Describe the manufacture of ethanol by fermentation. In your answer include: ● ● the names of the substances needed for fermentation ● ● the conditions needed for fermentation. 
11. Organic chemistry  →  11.3. Fuels
11. Organic chemistry  →  11.2. Naming organic compounds
11. Organic chemistry  →  11.6. Alcohols
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A student investigated the reaction between zinccarbonate and an excess of dilute hydrochloricacid. ZnCO3 + 2HCl ZnCl 2 + CO2 + H2O The rate of reaction can be found by measuring the decrease in the mass of the reaction mixture over time. Describe one other practical method for measuring the rate of this reaction. When 6.25 g of zinccarbonate is used, 2.20 g of carbondioxide is formed. Calculate the mass of zinccarbonate that forms 11.00 g of carbondioxide.  mass of zinc carbonate = g What effect do the following have on the rate of this reaction? ● ● Decreasing the temperature of the reaction mixture. All other conditions are kept the same. ● ● Increasing the concentration of hydrochloric acid. All other conditions are kept the same.  Carbon dioxide is formed: ● ● when an acid reacts with a carbonate ● ● as a product of the complete combustion of carbon-containing substances. State two other sources of carbondioxide.  
6. Chemical reactions  →  6.2. Rate of reaction
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An isotope of sodium is written as shown. 23Na Deduce the number of protons, electrons and neutrons in this isotope of sodium. number of protons number of electrons number of neutrons  State one medical use of radioactive isotopes. Draw the electronic structure of a sodium atom.  State the name of the particle which is lost when a sodium atom forms a sodium ion. Sodium reacts with water to form: ● ● an alkaline solution ● ● a gas which ‘pops’ with a lighted splint. Complete the word equation for the reaction of sodium with water. sodium + water +  The reaction of sodium with water is exothermic. What is meant by the term exothermic? Sodium reacts with oxygen to form sodium oxide. Is sodium oxide an acidic oxide or a basic oxide? Give a reason for your answer. The table shows some observations for the reaction of four metals with cold water and with hot water. metal reaction with cold water reaction with hot water calcium bubbles form rapidly bubbles form very rapidly lanthanum bubbles form slowly bubbles form very rapidly manganese no bubbles form bubbles form very slowly uranium bubbles form slowly bubbles form rapidly Use this information to put the four metals in order of their reactivity. Put the least reactive metal first. least reactive most reactive  
9. Metals  →  9.4. Reactivity series
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
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This question is about the halogens and compounds of the halogens. The properties of some halogens are shown in the table. element melting point in °C boiling point in °C density of liquid at its boiling point in g / cm3 atomic radius in nm chlorine –101 –35 0.099 bromine –7 3.12 0.114 iodine 4.93 0.133 astatine 6.35 Complete the table to estimate: ● ● the density of liquid chlorine ● ● the boiling point of iodine.  Describe the trend in the atomic radius of the halogens down the group. Predict the physical state of bromine at 50 °C. Give a reason for your answer. Bromine reacts with an aqueous potassium salt to form iodine and a different potassium salt. Complete the word equation for this reaction. bromine + iodine +  Fluorine is above chlorine in GroupVII of the Periodic Table. Explain, using ideas about the reactivity of the halogens, why chlorine does not react with aqueous sodium fluoride. Balance the chemical equation for the reaction of fluorine with ammonia. NH3 + F2 N2 + 6HF A compound of fluorine has the formula XeO3F2. Complete the table to calculate the relative molecular mass of XeO3F2. Use your Periodic Table to help you. type of atom number of atoms relative atomic mass xenon oxygen 3 × 16 = 48 fluorine  relative molecular mass =  The compound XeO3F2 readily undergoes reduction. What is meant by the term reduction? 
8. The Periodic Table  →  8.3. Group VII properties
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This question is about ammonia. When ammonia gas reacts with hydrogenchloride gas, white fumes of ammoniumchloride are formed. NH3 + HCl NH4Cl What type of chemical reaction is this? Draw a circle around the correct answer. decomposition neutralisation oxidation reduction Watch-glasses of aqueous ammonia and concentrated hydrochloricacid were placed near each other on a table. At first no white fumes were seen. After a short time, white fumes were seen between the watch-glasses. watch-glass of ammonia watch-glass of hydrochloric acid at the start a short time later dense white fumes Explain these observations using the kinetic particle model. Ammonia is used in the manufacture of fertilisers. Name the three elements present in most fertilisers which improve plant growth.  Aqueous ammonia can be used to test for aluminium ions and zinc ions. Complete the table to show the expected observations. ion observation on adding a small volume of aqueous ammonia observation on adding an excess of aqueous ammonia aluminium (Al 3+) zinc (Zn2+)  
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
6. Chemical reactions  →  6.3. Reversible reactions and equilibrium
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Magnesium is manufactured by the electrolysis of molten magnesium chloride. The negative electrode is made of iron. Suggest a non-metal which could be used for the positive electrode. Give a reason for your answer. Predict the products of the electrolysis of molten magnesium chloride at: the positive electrode the negative electrode.  The following statements are about the procedure for making crystals of hydrated magnesiumchloride from magnesium and dilute hydrochloric acid. A Leave the mixture until no more bubbles are seen. B Leave the mixture at room temperature to form more crystals. C Add an excess of magnesium to dilute hydrochloric acid. D Warm the filtrate to the point of crystallisation. E Filter off the crystals and dry between filter papers. F Filter off the excess magnesium. Put the statements A, B, C, D, E and F in the correct order. The first one has been done for you. C  Magnesium is a metal in GroupII of the PeriodicTable. Copper is a transition element. Copper has a higher melting point and a higher boiling point than magnesium. Describe two other properties of copper which are different from those of magnesium.  Chromatography can be used to separate a mixture of ions from different transition element compounds. Four samples, R, S, T and U, each containing transition element ions, were placed on a piece of chromatography paper. Two solutions, Y and Z, each containing only one type of transition element ion were also placed on the same piece of chromatography paper. The results of the chromatography are shown. R S T U Y Z Which sample, R, S, T or U, contains the same ions as both solutionY and solutionZ? Which sample, R, S, T or U, does not contain the same ions as either solution Y or solutionZ? In which sample, R, S, T or U, has the greatest number of transition element ions been separated? 
4. Electrochemistry  →  4.1. Electrolysis
9. Metals  →  9.4. Reactivity series
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