0620_w06_qp_2
A paper of Chemistry, 0620
Questions:
7
Year:
2006
Paper:
2
Variant:
0
Login to start this paper & get access to powerful tools
1
Use When Group I elements react with water, hydrogen gas is given off. The diagram shows the reaction of lithium, potassium and sodium with water. A B C Which one of these elements A, B or C is lithium? Balance the equation for the reaction of sodium with water by completing the left- hand side. Na + H2O 2NaOH + H2 Apart from fizzing, describe two things that you would see when sodium reacts with water. After the sodium had reacted with the water, the solution was tested with red litmus paper. What colour did the litmus paper turn? Give a reason for your answer. colour reason Examiner's Use Which of the following statements about sodium are true? Tick two boxes. It is made by reducing sodium oxide with carbon. It reacts with chlorine to form sodium chloride. It reacts readily with oxygen. It only conducts electricity when molten. Rubidium also reacts with water. How does the speed of reaction of rubidium with water compare with that of potassium with water? Sodium has only one stable isotope whereas potassium has several isotopes. What do you understand by the term isotopes? How many protons does sodium have in its nucleus? Use the Periodic Table to help you. How many electrons are there in an atom of potassium? Uranium has many isotopes. One of these is uranium-235 (235U). What is the main use of this isotope of uranium?
9. Metals  →  9.4. Reactivity series
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
8. The Periodic Table  →  8.2. Group I properties
Open
2
Use Copper can be extracted by heating copper carbonate with carbon. The copper carbonate breaks down into copper oxide and releases a gas. Complete the equation for this reaction. CuCO3 CuO + The copper oxide then reacts with the carbon. 2CuO + C 2Cu + CO2 heat Complete the following sentences using words from the list. endothermic exothermic halogen metal neutralised oxidised reduced In this reaction copper oxide is to copper. The copper obtained is a pinkish-brown The reaction is because heat is absorbed. State the name of the substance which is oxidised during this reaction. How would you test for the carbon dioxide given off in this reaction? test result Describe a test for aqueous copper ions and state the result. Examiner's Use Carbon is in Group IV of the Periodic Table. Draw a diagram to show how the electrons are arranged in an atom of carbon. To which Period in the Periodic Table does carbon belong? Organic compounds contain carbon and hydrogen. To which homologous series does the organic compound A belong? H H H C H H C H compound A State the name of compound A.
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
9. Metals  →  9.4. Reactivity series
Open
3
Use Lavandulol is found in lavender plants. The formula of lavandulol is shown below. CH2 CH3 CH3 CH2 CH3 C CH CH2 HO C C H Put a ring around the alcohol functional group in this formula. Is lavandulol a saturated or unsaturated compound? Give a reason for your answer. State the names of the two products formed when lavandulol is burnt in excess oxygen. and Lavandulol can be extracted from lavender flowers by distillation using the apparatus shown below. The lavandulol is carried off in small droplets with the steam. heat lavender flowers and water X A lavandulol water Examiner's Use State the name of the piece of apparatus labelled A. What is the temperature of the water at point X in the diagram? The lavandulol and water are collected in the beaker. What information in the diagram shows that lavandulol is less dense than water? Lavender flowers contain a variety of different pigments . A student separated these pigments using paper chromatography. The results are shown in the diagram below. chromatography paper Put an X on this diagram to show where the mixture of pigments was placed at the start of the experiment. How many different pigments have been separated? Draw a diagram to show how the chromatography apparatus was set up. On your diagram label • the solvent • the origin line Examiner's Use During chromatography, the solvent evaporates and then diffuses throughout the chromatography jar. What do you understand by the term diffusion? Ethanol can be used as a solvent in chromatography. Draw the formula for ethanol showing all atoms and bonds. Which of the following statements about ethanol are true? Tick two boxes. It is a carboxylic acid. It is a product of the fermentation of glucose. It is an unsaturated compound. It is formed by the catalytic addition of steam to ethene.
12. Experimental techniques and chemical analysis  →  12.3. Chromatography
Open
4
Use This question is about compounds. What do you understand by the term compound? Complete the table below to show the formulae and uses of some compounds. compound relative number of atoms present formula use calcium oxide Ca = 1 O = 1 CaO sodium chloride Na = 1 Cl = 1 table salt calcium carbonate Ca = 1 C =1 O = 3 NH4NO3 in fertilizers Calculate the relative formula mass of NH4NO3.
3. Stoichiometry  →  3.1. Formulae
3. Stoichiometry  →  3.2. Relative masses of atoms and molecules
Open
5
Use The list shows part of the reactivity series. strontium calcium magnesium iron copper more reactive less reactive Calcium is manufactured by the electrolysis of molten calcium chloride. Suggest why calcium is extracted by electrolysis. Equal sized pieces of magnesium, strontium and calcium are placed in water. Some observations about these reactions are shown in the table. Complete the box for strontium. metal observations magnesium Gives off a few bubbles of gas with hot water. Dissolves very slowly. calcium Gives off bubbles steadily with cold water. Dissolves slowly. strontium When water is added to calcium carbide, acetylene and calcium hydroxide are formed. State a use for acetylene. A solution of calcium hydroxide is alkaline. Complete and balance the equation for the reaction of calcium hydroxide with hydrochloric acid. Ca(OH)2 + 2HCl CaCl2 + What type of chemical reaction is this? Examiner's Use A student used the apparatus shown below to calculate the concentration of a solution of calcium hydroxide. calcium hydroxide solution hydrochloric acid A State the name of the piece of apparatus labelled A. Describe how the pH of the solution in the flask changes as the hydrochloric acid is added.
9. Metals  →  9.4. Reactivity series
12. Experimental techniques and chemical analysis  →  12.5. Identification of ions and gases
Open
6
Use The diagram shows the structure of lead bromide. Pb2+ Pb2+ Pb2+ Pb2+ Pb2+ Pb2+ Br – Br – Br – Br – Br – Br – Br – Br – Br – Br – Br – Br – What is the simplest formula for lead bromide? What type of structure and bonding is present in lead bromide? Choose two words from the following: atomic covalent giant ionic metallic molecular Lead bromide is electrolysed using the apparatus shown below. + – heat molten lead bromide electrodes B A C Which letter, A, B or C represents the cathode? Examiner's Use State the name of a metal which can be used for the electrodes. Why does lead bromide have to be molten for electrolysis to occur? State the name of the products formed during this electrolysis; at the anode, at the cathode. A student bubbled chlorine gas through an aqueous solution of sodium bromide. Complete the equation for this reaction. Cl2 + 2NaBr + 2NaCl chlorine sodium bromide bromine sodium chloride What colour is the solution at the end of the reaction? An aqueous solution of iodine does not react with a solution of sodium bromide. Explain why there is no reaction. Examiner's Use Bromine becomes decolourised when it reacts with ethene. Draw the structure of ethene showing all atoms and bonds. Which one of the following, A, B, C or D, shows the correct structure of the product formed when bromine reacts with ethene? H H H C Br H C Br A H H H H C Br H C C H H H C Br Br H C D H C Br Br C H B answer
4. Electrochemistry  →  4.1. Electrolysis
11. Organic chemistry  →  11.5. Alkenes
Open
7
Use The table gives some information about the properties of some metals. metal melting point /°C colour of chloride A pink B white C white D brownish-black Which two of the metals A to D are transition metals? Give a reason for your answer. metals reason When iron powder reacts with warm sulphuric acid, hydrogen is given off. Fe + H2SO4 FeSO4 + H2 State the name of the salt made in this reaction. Examiner's Use A student used the apparatus shown below for investigating the speed of the reaction between iron and sulphuric acid. water sulphuric acid iron powder Describe how this apparatus can be used to investigate the speed of this reaction. The student repeated the experiment with different concentrations of sulphuric acid. In each experiment the mass of iron powder was the same and the temperature was kept at 30°C. The results are shown in the table. concentration of sulphuric acid / moles per dm3 speed of reaction /cm3 hydrogen per second 0.4 4.2 0.8 8.5 1.6 17.0 Use the information in the table to help you work out how the speed of the reaction is affected by the concentration of sulphuric acid. What will happen to the speed of the reaction if lumps of iron are used instead of iron powder? Examiner's Use What will happen to the speed of the reaction if it is carried out at 20°C rather than at 30°C?
6. Chemical reactions  →  6.2. Rate of reaction
9. Metals  →  9.4. Reactivity series
Open