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1 Oxford ambridge and RS S Level hemistry (Salters) H033/01 Foundations of chemistry Friday 26 May 2017 Morning Time allowed: 1 hour 30 minutes * * You must have: the ata Sheet for hemistry (Salters) (sent with general stationery) You may use: a scientific or graphical calculator * H * First name Last name entre number andidate number INSTRUTIONS Use black ink. H pencil may be used for graphs and diagrams only. omplete the boxes above with your name, centre number and candidate number. nswer all the questions. Write your answer to each question in the space provided. If additional space is required, use the lined page(s) at the end of this booklet. The question number(s) must be clearly shown. o not write in the barcodes. INFORMTION The total mark for this paper is 70. The marks for each question are shown in brackets [ ]. This document consists of 20 pages. [601/5446/9] (NH/GW) /4 OR is an exempt harity Turn over

2 2 SETION You should spend a maximum of 25 minutes on this section. nswer all the questions. Write your answer to each question in the box provided. 1 How many hydrogen atoms are there in 1 mol of methanol? Which row could be correct for solids with the structure type named? Structure type Melting point Solubility in water Electrical conductivity ionic high soluble high metallic high insoluble high ionic low soluble high metallic low insoluble low 3 What is a correct measure of percentage atom economy? mass of useful products 100 / mass of reactants amount of products 100 / amount of reactants M r of products 100 / M r of reactants M r of useful products 100 / M r of reactants

3 4 What is correct about hydrogen bromide? 3 It reacts with concentrated sulfuric acid to form r 2 and H 2 S. It forms white fumes with ammonia. Its M r is It does not decompose on heating. 5 For which purpose is distillation used? to allow a liquid to boil without the loss of vapour to purify a liquid product to remove an involatile impurity to allow further reaction without the loss of product 6 What is correct about a green chemistry process? It makes waste products that are easier to separate. It makes processes cheaper. It uses organic solvents. It reduces the number of steps necessary. 7 sample of gas, volume V, has its temperature raised from 0 to 20. The pressure remains constant. What is the new volume? V 0.93 V 1.07 V 20 V Turn over

4 4 8 Which row is correct for the silver halide shown? Halide olour Solubility in ammonia silver chloride white soluble silver bromide yellow insoluble silver iodide yellow soluble silver iodide cream partially soluble 9 H 3 l can be converted to H 3 NH 2 in one step. What is correct about this process? The reaction is substitution of l by NH 3. The product is an amide. The reagent is NH 4 +. The reagent is a nucleophile. 10 H 3 l and H 3 I both react with hydroxide ions. What is correct about these reactions? H 3 l reacts faster because the l bond is more polar than the I bond. H 3 I reacts faster because the l bond is stronger than the I bond. oth form ethanol. In each case, homolytic bond fission occurs.

5 11 What will react with a phenol? 5 sodium carbonate sodium hydroxide ethanoic acid acidified potassium dichromate 12 When are insoluble impurities removed during recrystallisation? when the hot solution is filtered as the solution cools when the crystals are filtered off when the crystals are washed 13 Which of these is classified as an elimination reaction? H 3 OOH + 2 H 5 OH H 3 OO 2 H 5 + H 2 O uso 4 5H 2 O uso 4 + 5H 2 O 2 H 5 OH 2 H 4 + H 2 O 17 H H H 14 Turn over

6 6 14 uo 3 uo + O g of copper carbonate (M r = 123.5) is heated. What is the volume of O 2 produced at room temperature and pressure? 120 cm dm cm 3 12 dm 3 15 What is correct about a sodium chloride lattice? There are attractions between ions of different charge. The sodium ions are larger than the chloride ions. The numbers of sodium ions and chloride ions are not equal. Each sodium ion is surrounded by four chloride ions. 16 What is correct about an exothermic reaction? Heat is taken in. More bonds are made than broken. The sign of H is positive. It is represented by a downwards arrow on an enthalpy profile diagram. 17 What is the functional group in the compound H 3 OOO 2 H 5? carboxylic acid ester acid anhydride ketone

7 18 This question concerns four compounds each with four carbon atoms. 1. H 3 H 2 H 2 H 2 OH 2. H 3 H(H 3 )H 2 OH 7 3. H 3 H 2 H 2 HO 4. H 3 H 2 OH 2 H 3 What is the order of their boiling points, largest first? Which has the largest bond angle? F 3 F 4 NF 3 OF 2 20 Nitrogen monoxide, NO, reacts instantaneously in air to form NO 2. What is an explanation for this? NO is a radical taking part in a termination reaction. the activation enthalpy for the reaction is low. oxygen is a very reactive gas. NO 2 is less stable than NO. Turn over

8 8 SETION nswer all the questions. 21 The presence of chlorine in organic compounds can be seen from their mass spectra. hlorine has two isotopes in the proportions as shown. 35 l 75.53% 37 l 24.47% (a) (i) Give the number of protons, neutrons and electrons in an atom of 35 l. protons... neutrons... electrons... (ii) Give the electron configuration, using sub-shells and atomic orbitals, of an atom of 37 l.... (iii) raw a diagram to show the shape of a p-orbital and indicate how many electrons it can hold. number of electrons:... (b) alculate a value for the r of chlorine. Give your answer to two decimal places. r =... [2]

9 (c) The mass spectrum of chloroethane, 2 H 5 l, is shown below. The presence of chlorine isotopes causes two mass peaks relative abundance m/z (i) Give the formula of the ion responsible for the peak at m/z (ii) Explain the ratio of the heights of the peaks at m/z 64 and m/z [2] (iii) Suggest the formula of the ion that gives the peak at m/z (d) hloroethane can be converted to ethanol. The infrared spectrum of ethanol has some absorptions that are not present in the infrared spectrum of chloroethane. Give the range of one of these absorptions and the corresponding bond. bsorption... ond... Turn over

10 10 22 Some students carry out experimental work involving salts. Salt is used as a fertiliser. The students are given a sample of salt to analyse. They carry out a flame test. The result is a lilac flame. They dissolve salt in water and add hydrochloric acid followed by barium chloride solution. The result is the formation of a white precipitate. (a) Name salt.... (b) The lilac flame colour is from a prominent line in the atomic emission spectrum of salt. (i) escribe the appearance of an atomic emission spectrum.... (ii) The lilac line in the spectrum of the salt occurs at 405 nm. alculate the energy associated with this wavelength in kj mol 1. (1 nm = 10 9 m) energy =...kj mol 1 [3] (c) The students are then asked to make a pure dry sample of lead chloride, an insoluble salt. They suggest mixing lead nitrate solution and sodium chloride solution, then filtering and drying the solid formed. (i) Write a full equation for the reaction that occurs.

11 (ii) 11 The students method would not produce a pure dry sample of lead chloride. State how to improve the method.... [2] (d) The students are given a mol dm 3 solution of Na 2 O 3. They titrate this against a solution of hydrochloric acid. Na 2 O 3 + 2Hl 2Nal + H 2 O + O 2 (i) 25.0 cm 3 of the Na 2 O 3 solution requires 23.6 cm 3 of Hl. alculate the concentration of the Hl. concentration =... mol dm 3 [2] (ii) student says: There is no point writing mol dm 3 for the Na 2 O 3 solution. Writing 0.15 mol dm 3 means the same thing. iscuss whether or not the student s statement is correct.... [2] Turn over

12 12 (e) The students are then given some FeSO 4 xh 2 O. The students dissolve the solid to make FeSO 4 (aq). (i) escribe a test they can do on this solution to identify the cation. Test and its result (ii) Write an ionic equation, with state symbols, for the reaction that occurs in this test. (f) The students then heat a sample of solid FeSO 4 xh 2 O. They find that 9.45 g of FeSO 4 xh 2 O gives 5.16 g of solid after heating. (i) escribe how the students could ensure that all the water had been lost.... (ii) alculate the value of x. x =... [2]

13 23 Some students are given samples of two liquid hydrocarbons, and, to test as fuels. 13 Fuel Name Skeletal formula Molecular formula liphatic or aromatic? Saturated or unsaturated? yclohexane 7 H 16 (a) omplete the table above, filling the empty boxes. [3] (b) (i) alculate a value for the f H of fuel using the data below. 7 H 16 (l) + 11O 2 (g) 7O 2 (g) + 8H 2 O(l) c H = 4811 kj mol 1 fuel ompound f H / kj mol 1 O 2 (g) 394 H 2 O(l) 286 f H =... kj mol 1 [2] Turn over

14 (ii) 14 sample of a fuel produces 46 g of carbon dioxide when burned. alculate the volume (in cm 3 ) that this would occupy at 273 K and 150 kpa. Give your answer to an appropriate number of significant figures. volume =... cm 3 [3] (c) The students burn the fuels and separately in the apparatus shown below. Their aim is to compare the energies produced on combustion. thermometer water calorimeter spirit burner (i) State the measurements that the students would make to calculate a value for the energy produced. Show how these measurements would be used to calculate this energy.... [2]

15 (ii) 15 State and explain two improvements that could be made to increase the accuracy of the calculated value of the energy produced [4] (d) oth the fuels would produce NO if used in a car engine. Explain how NO is produced in a car engine Turn over

16 16 24 Ethyl ethanoate, H 3 OO 2 H 5, is an ester with many uses, including removing the caffeine from coffee. (a) Ethyl ethanoate can be made in the laboratory by the reaction shown below. H 3 OOH + 2 H 5 OH H 3 OO 2 H 5 + H 2 O This reaction can reach dynamic equilibrium. What can be said about the forward and back reactions once an equilibrium position has been reached? (b) Ethyl ethanoate will dissolve caffeine since it has similar intermolecular bonds. H 3 N O H 3 N O N N H 3 caffeine (i) affeine contains some atoms that have greater electronegativity than carbon. Explain the term electronegativity....

17 (ii) 17 omplete the dot-and-cross diagram for ethyl ethanoate. H H O H H H H O H H (iii) State and explain the bond angle around the ester group carbon (shown in bold) in the structure above.... [4] (iv) Name the strongest intermolecular bond that can form between caffeine and ethyl ethanoate.... EN OF QUESTION PPER

18 18 ITIONL NSWER SPE If additional space is required, you should use the following lined page(s). The question number(s) must be clearly shown in the margin(s).

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