Page 37 - Hybrid PBD 2022 Tg 5 - Kimia

Kimia Tingkatan 5 Bab 3

3. Tentukan haba penyesaran kuprum oleh zink.
Determine the heat of displacement of copper by zinc.
[muatan haba tentu air, c = 4.2 J kg °C ]
–1
–1
[specific heat capacity of water, c = 4.2 J kg °C ]
–1
–1
(a) Bilangan mol kuprum(II) sulfat, CuSO 4 = 0.5 × 25 = 0.0125 mol
Number of moles of copper(II) sulphate, CuSO 4 1000
(b) Perubahan haba = mcθ = 25 × 4.2 × 10 J = 1050 J
Heat change
(c) Tuliskan persamaan ion : Cu + Zn → Cu + Zn
2+
2+
Write the ionic equation
(d) Haba pemendakan / Heat of precipitation:
1 mol Cu bertindak balas dengan 1 mol Zn → 1 mol Cu dan 1 mol Zn .
2+
2+
1 mole of Cu reacts with 1 mole of Zn → 1 mole of Cu and 1 mole of Zn .
2+
2
Maka, 0.0125 mol Cu bertindak balas dengan 0.0125 mol Zn → 0.0125 mol Cu dan
2+
0.0125 mol Zn .
2+
Hence, 0.0125 mole of Cu reacts with 0.0125 mole of Zn → 0.0125 mole of Cu and 0.0125 mole of Zn .
2+
2+
1050
ΔH = = −84000 J mol // −84 kJ mol
−1
−1
0.0125
4. Tentukan haba penyesaran kuprum oleh magnesium.
Determine the heat of displacement of copper by magnesium.
–1
–1
[muatan haba tentu air, c = 4.2 J kg °C ]
[specific heat capacity of water, c = 4.2 J kg °C ]
–1
–1
(a) Bilangan mol kuprum(II) sulfat, CuSO 4 = 0.5 × 25 = 0.0125 mol
1000
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Number of moles of copper(II) sulphate, CuSO 4
(b) Perubahan haba = mcθ = 25 × 4.2 × 15 J = 1575 J
Heat change
(c) Tuliskan persamaan ion : Cu + Mg → Cu + Mg 2+
2+
Write the ionic equation
(d) Haba pemendakan / Heat of precipitation:
1 mol Cu bertindak balas dengan 1 mol Mg → 1 mol Cu dan 1 mol Mg .
2+
2+
1 mole of Cu reacts with 1 mole of Mg → 1 mole of Cu and 1 mole of Mg .
2+
2+
Maka, 0.0125 mol Cu bertindak balas dengan 0.0125 mol Mg → 0.0125 mol Cu dan
2+
0.0125 mol Mg .
2+
Hence, 0.0125 mole of Cu reacts with 0.0125 mole of Mg → 0.0125 mole of Cu and 0.0125 mole of Mg .
2+
2+
1575
ΔH = = −126000 J mol // −126 kJ mol
−1
−1
0.0125
5. Lukis gambar rajah aras tenaga bagi tindak balas penyesaran kuprum oleh zink dan magnesium.
Draw the energy level diagrams for the displacement of copper by zinc and magnesium.
Cu + Zn
2+
Gambar rajah aras tenaga bagi penyesaran Tenaga
kuprum oleh zink Energy ΔH= –84.0 kJ mol –1
Energy level diagram of displacement of copper by zinc Cu + Zn 2+
2+
Gambar rajah aras tenaga bagi penyesaran Cu + Mg
kuprum oleh magnesium Tenaga ΔH= –126 kJ mol –1
Energy level diagram of displacement of copper by Energy
magnesium Cu + Mg 2+
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03 Hybrid Kimia Tg5.indd 108 05/11/2021 4:18 PM