Page 291 - Chemistry

0.005 x 1000 = answer in moles
Titre in a

c) 10cm3 of A contains moles in (b) above
1000cm3 of A contains
Ans in b x 100 = Answer
10

NB This answer should be close or equal to 4.0M
Question 2
TABLE 3 (5 mks)
Distributed as follows
i) Complete table (1mk)
- Award 1 mk for completely filled table (at least 8 values)

ii) Use of decimals (2 mks)
- Use of decimals for temperature readings award 1 mk
- Use of correct decimals for time readings award 1 mk

NB Penalize ½ mk if i/t is given as fraction

iii) Trends
Trend for temperature 1mk (i.e. should be decreasing)
Trend for time 1 mk(should be increasing)

GRAPH
Should be distributed as follows:
- Labelling the axes ½ mk for both axes
- Scale ½ mk (at least ¾ pg)
- Plotting I mk
- Shape (accept a curve and award 1 mk)

Question 3
Test for solid K
Observations Inferences
a) - colorless liquid condenses at the cooler parts of the - Presence of hydrated substance
test tube - Contains water of crystallization
- Cracking sound produced
b)i) - White precipitate soluble in excess - Al3+, Zn2+ or Pb2+ ions present
3 stated 1mk, 2 stated ½ mk
ii) No white precipitate formed - Presence of AL3+ and Zn2+
- NB must have been correctly
inferred in part b(i)
iii) White precipitate formed Presence of SO2-4 or CL-
Award 1 mk for any 2
Test for solid F Award ½ mk for any 1 10n given
c) Effervescence or bubbles produced Presence of H+, H3O+, R-COOH
d) Decolorises acidified KMnO4 or turns KMnO4 to Presence of reducing agent
colourless C = C – C = C-
Or ROH, SO3
e) Fruity or sweet smell R- COOH confirmed

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