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Question 18M.2.sl.TZ1.c

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Date May 2018 Marks available [Maximum mark: 2] Reference code 18M.2.sl.TZ1.c
Level sl Paper 2 Time zone TZ1
Command term Determine Question number c Adapted from N/A
c.
[Maximum mark: 2]
18M.2.sl.TZ1.c

Urea, (H2N)2CO, is excreted by mammals and can be used as a fertilizer.

Urea can be made by reacting potassium cyanate, KNCO, with ammonium chloride, NH4Cl.

                                      KNCO(aq) + NH4Cl(aq) → (H2N)2CO(aq) + KCl(aq)

Determine the maximum mass of urea that could be formed from 50.0 cm3 of 0.100 mol dm−3 potassium cyanate solution.

[2]

Markscheme

n(KNCO) «= 0.0500 dm3 × 0.100 mol dm–3» = 5.00 × 10–3 «mol»

«mass of urea = 5.00 × 10–3 mol × 60.07 g mol–1» = 0.300 «g»

 

 

Award [2] for correct final answer.

[2 marks]

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