Page 8 - Modul A+1 Kimia Tingkatan 5

Katod (–) Pepejal perang terenap. Gelembung gas dibebaskan. Gas tidak
Cathode (–) Brown solid is deposited berwarna menghasilkan bunyi “pop”
dengan kayu uji bernyala.
Gas bubbles released. Colourless gas
produces a “pop” sound with the glowing Bab 1
wooden splinter.

Mentafsir data/ Interpreting data: TP 4

Elektrolit Larutan kuprum(II) sulfat, CuSO Asid sulfurik cair, H SO
4 2 4
Electrolytes Copper(II) sulphate, CuSO solution Dilute sulphuric acid, H SO
4 2 4
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(a) Ion yang hadir di dalam CuSO ➝ Cu + SO 2– H SO ➝ 2H + SO 2–
2+
+
4 4 2 4 4
+
elektrolit. H O H + OH – H O H + OH –
+
2
2
Ions present in the
electrolytes.
2–
2–
(b) Ion yang tertarik ke anod Anod/ Anode (+): SO , OH – Anod/ Anode (+): SO , OH –
4 4
dan katod. Katod/ Cathode (–): H , Cu 2+ Katod/ Cathode (–): H +
+
Ions attracted to the anode
and cathode.
–
–
(c) Ion yang dinyahcas Anod/ Anode: OH (H O) Anod/ Anode: OH (H O)
2 2
di anod dan di katod. Alasan/ Reason: Alasan/ Reason:
–
0
–
0
Nyatakan alasan. E bagi ion OH kurang positif E bagi ion OH kurang positif
2–
2–
Ions discharged at the berbanding ion SO . berbanding ion SO .
4 4
anode and cathode. State E of OH ion is less positive than E of OH ion is less positive than SO ion.
0
–
–
0
2–
4
the reason. SO ion.
2–
4
+
Katod/ Cathode: Cu 2+ Katod/ Cathode: H (H O)
2
Alasan/ Reason: Alasan/ Reason:
2+
0
E bagi ion Cu lebih positif –
+
berbanding ion H .
E of Cu ion is more positive than
2+
0
H ion.
+
(d) Setengah persamaan Anod/ Anode: Anod/ Anode:
tindak balas di anod dan 2H O ➝ O + 4H + 4e – 2H O ➝ O + 4H + 4e –
+
+
2 2 2 2
di katod.
Half-equations for reaction Katod/ Cathode: Katod/ Cathode: –
–
2+
–
at the anode and cathode. Cu + 2e ➝ Cu 2H O + 2e ➝ H + 2OH
2
2
Perbincangan/ Discussion: TP 5
1. Larutan akueus kuprum(II) sulfat, CuSO terdiri daripada ion kuprum(II), Cu dan ion sulfat, SO .
2–
2+
4
4
2+
The copper(II) sulphate, CuSO aqueous solution comprises of copper(II) ion, Cu and sulphate ion, SO 2− .
4 4
(a) Apabila suis dihidupkan, ion kuprum(II), Cu dan molekul air, H O bergerak ke katod . Pada
2+
2
2–
masa yang sama, ion sulfat, SO dan molekul air, H O bergerak ke anod .
4 2
2+
When the switch is turned on, copper(II) ions, Cu and water molecules, H O move to the cathode .
2
At the same time, sulphate ions, SO 2− and water molecules, H O move to the anode .
4 2
0
(b) Pada anod , nilai E air, H O adalah kurang positif daripada ion
2
2–
sulfat, SO . Maka, molekul air, H O dioksidakan untuk membentuk
4 2
gas oksigen, O dan ion hidrogen, H +
2 .
0
At the anod , E value of water, H O is less positive than sulphate ion, SO 2− . Therefore,
2 4
water molecules, H O are oxidised to form oxygen gas, O and hydrogen ions, H + .
2
2
0
+
–
O + 4H + 4e  2H O E = +1.23 V
2 2
–
0
S O 2– + 2e  2SO E = +2.01 V
2–
2 8 4
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