SASS Chem Haber Process

Page 1 ST ANDREW’S SECONDARY SCHOOL NAME CLASS DATE CHEMISTRY 18.1 The Haber Process AMMONIA Assessment for Learning 1 The equation shows the reaction for the manufacture of ammonia. N2 (g) + 3 H2 (g)⇌ 2 NH3 (g) Which change will not increase the yield of this reaction? A Addition of Fe catalyst B Decrease in temperature C Increase in molar volumes of each reactant D Increase in pressure 2 In the Haber process, nitrogen and hydrogen react to form ammonia. N2 (g) + 3 H2 (g) ⇌ 2 NH3 (g) ∆H = –92 kJ Which factor increases both the speed of reaction and the amount of ammonia formed? A Addition of Fe catalyst B Decrease in temperature C Increase in pressure D Increase in temperature 3 The diagram shows the main stages in the manufacture of ammonia. Which of the following best describes the process labelled X? A Ammonia is returned to the start of the process to form a larger amount of the product. B The gases are cooled to cause ammonia to form a liquid. C Unreacted hydrogen only is recycled. D Unreacted hydrogen and nitrogen are recycled. [Turn Over CHEMISTRY (G3) 6092 MARKING SCHEME Section A [5 Marks] 1 2 3 4 5 D B B D C Section B Qn Answers Mark Remarks 6 (a)(i) A and H [1] 6 (a)(ii) B [1] 6 (a)(iii) D [1] 6 (a)(iv) C and E or C and G [1] 6 (b) F F contains 10 electrons arranged in 3 electron shells, with its 2nd electron shell incompletely filled with only 6 electrons. [1] [1] Accept any plausible answers. 6 (c)(i) H– [1] Rej. chemical name / G–. 6 (c)(ii) Aluminium [1] 7 (a) X : Liquid Y : Liquid and Solid Z : Solid [1] deducted for each mistake [2] Rej. additional state(s) provided for each stage. 7 (b)(i) 113.7 [1] 7 (b)(ii) Heat energy is released to the surroundings (during freezing) as the particles are attracted to each other to form a solid. [1] 8 (a) –69 ℃ [1] 8 (b)(i) MgCl2 SCl2 [4] MgCl2 [1] stoichiometry and charge on both ions. [1] octet structure. SCl2 [1] no. of electrons shared. [1] no. of non-bonding / lone pair of electrons. ✓╳╳ Mg╳╳╳╳╳╳ 2+Cl−●●●●●●●╳2 ●╳SCl╳╳ ╳╳╳╳ Cl╳╳ ╳╳╳╳●╳●●●● ST ANDREW’S SECONDARY SCHOOL WEIGHTED ASSESSMENT 2 2022 SECONDARY 3 8 © UCLES 2018 5070/11/O/N/18 20 T h r e e s e p a r a t e m i x t u r e s o f a s o l u t i o n a n d a s o l i d a r e m a d e , a s s h o w n i n t h e t a b l e . The mixtures are warmed. In which mixtures does gas form? NaOH(aq) and NH4Cl (s) H2SO4(aq) and NH4Cl (s) H2SO4(aq) and Mg(s) A key B = gas forms C = no gas forms D 21 I n s o l u b l e s a l t s a r e p r e p a r e d b y r e a c t i n g a q u e o u s s o l u t i o n s o f s o l u b l e s a l t s . A p r e c i p i t a t e f o r m s . Which pairs of aqueous solutions form a precipitate? 1 barium chloride and nitric acid 2 barium c