Page 419 - SUBSEC October 2017_Neat

02112032/CAPE/SPEC/MS/2017
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CHEMISTRY
UNIT 1 — PAPER 032
MARK SCHEME

Question 1

S.O.: Module: 1 ----3.8, 3.9
KC UK XS
(a)

Burette readings KMnO 4 /H +

Reading/cm 3 1 2 3

Final
6

Initial

Difference

Correct burette readings [6 marks]

(If one incorrect = 5 marks)

(If two incorrect = 4 marks)
(If THREE incorrect = 3 marks)

(If FOUR incorrect = 2 marks)

(If FIVE incorrect = 1 mark)

(More than FIVE incorrect = 0 marks)

Volumes recorded to 2 decimal places – 1 mark

(b) 1

Pink tinge [1 mark]

(c) 1

Candidate’s average of closest values [1 mark]

(d)

1
2+
3
No. of moles of Fe (aq) in 1 dm

39
=
392
= 0.1 mol dm -3 [1 mark]
(e)

2+ 3
No. of moles Fe in 25 cm = (0.1 x 0.025) = 0.0025 moles 1
[1 mark]