Page 297 - Chemistry

TABLE B;
Initial temp of CuSo4(c ) 25.5
Final temp of CuSO4 48.0
Temp change T(C ) 22.5

a) i) Exothermic// there is temperature rise heat energy is released to the environment
25
ii) Moles of CuSO4(aq) = 0.2 x / 1000 = 0.005
-1
-1
b) i) H = 25gx4.2Jg K x5.5K (OR T)
c) i) Powdered metals have increased surface are many metal particles with come in
contact
with HCL acid and react
ii) Grey// metallic grey
d) - Metal A dissolves in CuSO4(aq) solution and a green/ pale green solution is formed
- The blue colour of copper (II) sulphate solution fades/ disappears. Brown solid
deposited
- Metal A displaces copper; from its solution implying that A(q) is more reactive than
Cu (s)

-1
-1
e) i)  H = 25gx4.2Jg K x T (22.5) K = 2362JJ

If 0.5g _______ 2362.5J
65g _______ (65x2362.5) J = 307125J mol = 307.125KJmol
0.5

ii) B, A
_________ Decreasing reactivity

B gave higher  T// more heat energy was released when B reacted with CuSO4(aq)

Procedure;

Table of results
EXPERIMENT I II III
Final Vol. of solution C (cm3)
Initial Vol.of solution C (cm3)
Vol.of solution C used (cm3)

1. a) Volume of pipette = 25cm3

b) Average volume of C = 38.5 + 38.5 + 38.5 = 115 = 38.5
3 3

c) Moles of solution C = 0.1 x 38.5 / 1000 = 0.00385

d) i) HCL (aq) + MOH (aq) _________ MCL (aq) + H 2O (L)

Penalize ½ for wrong or missing s

+
-
ii) H (aq) + OH (aq) _______ H 2O (L)
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