Page 307 - Chemistry

H
H H

H – C = C
– C – C - H

H H
H H

= Correct answer  1(should be a whole number)
Q 2. Table
Each entry ½ mark
- Penalize ½ mark to a maximum of 1 mark for unrealistic values
- Penalize ½ mark mixing decimal numbers and whole numbers

a) i) Labeling ( ½ mark)
ii) Scale (½ mark)
iii) Plotting (2 marks)
iv) Line/ curve (1 mark)

b) i) 1. x 5  ½
1000
= 0.005  ½
2+
c) Pb : I -
0.0025: 0.005  1
1 : 2  1

d) Pb (NO 3) 2(aq) + 2KI (aq) PbI (s) + 2KNO 3 (aq)
Balanced  1
States symbol 1

-
e) Pb 2+ (aq) + 2I (aq) PbI 2(s)
Balance  ½
States  ½
f) To make the setting of precipitate faster 1

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