Page 19 - Modul A+1 Kimia Tingkatan 5

BAB 1 (iii)
Soalan Berformat SPM Elektrod X/ Electrode X
Anod/ Anode (+)
Kertas 1/ Paper 1 SO , OH – [1]
2–
4
1. D 2. B 3. A 4. B 5. C Ion tertarik OH dipilih untuk nyahcas sebab
–
6. B 7. A 8. D 9. D 10. B kepada kepekatannya lebih tinggi.
Ions attracted to OH is chosen for discharge because of its
–
Kertas 2/ Paper 2 higher concentration. [2]
Bahagian A/ Section A
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1. (a) (i) Bikar B/ Beaker B Setengah 4OH → 2H O + O + 4e – [1]
persamaan
–
(ii) G 2 2
Half-equation
Elektrod karbon Elektrod zink Elektrod kuprum Pemerhatian Gelembung gas tidak berwarna
Carbon electrodes Zinc electrode Copper electrode
Observation Colourless gas bubbles [1]
3
(b)
A B
Larutan kuprum(II) sulfat Bahan Plumbum(II) bromida Naftalena
(iii) Keamatan warna biru berkurang. Kepekatan ion Substance Lead(II) bromide Naphthalene
Copper(II) sulphate solution
Cu berkurang kerana dinyahcas.
2+
The intensity of the blue colour decreases. The Keadaan Pepejal Leburan Pepejal Leburan
concentration of Cu ions decreases due to State Solid Molten Solid Molten
2+
discharge. Tidak Tidak Tidak
(iv) Oksigen. Menyalakan kayu uji berbara. mengkonduksi Mengkonduksi mengkonduksi mengkonduksi
Oxygen. Ignites the glowing wooden splinter. Inferens arus elektrik arus elektrik arus elektrik arus elektrik
(b) (i) Cu + 2e → Cu Inference Does not Conduct Does not Does not
2+
–
Zn → Zn + 2e – conduct electricity conduct conduct
2+
(ii) Gas hidrogen. Ion H daripada asid dinyahcas electricity electricity electricity
+
+
Hydrogen gas. H ions from acid are discharged. Ion tidak Ion bergerak Molekul Molekul
2. (a) (i) Kuprum/ Copper Penerangan bergerak bebas neutral neutral
(ii) Besi lebih elektropositif daripada kuprum. Besi Explanation bebas Ions are free Neutral Neutral
akan mengion terlebih dahulu membentuk ion Fe Ions are not moving molecules molecules
2+
yang menghasilkan warna biru tua dengan larutan free moving
kalium heksasianoferat(III).
Iron is more electropositive than copper. Iron will Bahagian C/ Section C
ionise first to form Fe ions which produce dark 4. (a) Apabila ditambah kepada larutan kalium iodida, KI, air
2+
blue colour with potassium hexacyanoferrate(III) klorin mampu menyesarkan iodin daripada larutan kalium
solution.
(iii) Besi/ Iron iodida, KI. Larutan tidak berwarna menjadi perang.
When added to potassium iodide, KI solution, chlorine
Fe → Fe + 2e – water is able to displace iodine from potassium iodide, KI
2+
(b) (i) Zink/ Zinc solution. Colourless solution turns brown. [1]
(ii) Zink lebih elektropositif daripada besi. Zink akan Cl + 2KI → 2KCl + I [1]
2
mengion terlebih dahulu dan menghalang besi Cl + 2e → 2Cl Penurunan. Terima elektron
2
–
–
daripada berkarat. 2 Reduction. Accepts electron [1]
Zinc is more electropositive than iron. Zinc will 2I → I Pengoksidaan. Buang elektron
–
ionise first and prevent iron from rusting. 2 Oxidation. Releases electron [1]
(iii) Zink/ Zinc (b) Apabila serbuk zink ditambah kepada larutan ferum(III)
Zn → Zn + 2e – sulfat, Fe (SO ) dan dipanaskan perlahan-lahan, larutan
2+
4 5
2
perang berubah menjadi hijau muda.
Bahagian B/ Section B When zinc powder is added to iron(III) sulphate, Fe (SO )
4 3
2
solution and heated gently, the brown solution turns pale
3. (a) (i) Jenis elektrod/ Type of electrode green.
(ii) [2]
Katod/ Cathode (–) Anod/ Anode (+) Zn → Zn + 2e Pengoksidaan. Nombor pengoksidaan
2+
–
Ion Cu dinyahcas Cu terbentuk bertambah daripada 0 ke +2
2+
2+
Oxidation. Oxidation number increases
Ion Cu discharged [1] Cu formed [1] from 0 to +2 [2]
2+
2+
Setengah Fe + e → Fe Penurunan. Nombor pengoksidaan
3+
–
2+
persamaan Cu + 2e → Cu [1] Cu → Cu + 2e [1] berkurang daripada +3 ke +2
–
2+
2+
–
Half-equation Reduction. Oxidation number decreases
from +3 to +2 [2]
Katod menebal Anod menipis
Pemerhatian Cathode becomes Anode becomes ATAU/ OR
Observation thicker [1] thinner [1] Apabila air klorin ditambah kepada larutan ferum(II)
sulfat, FeSO larutan hijau muda berubah menjadi perang.
Jawapan When chlorine water is added to iron(II) sulphate, FeSO 4
4
solution, the pale green solution turns brown.
[2]

Cl + 2e → 2Cl Penurunan. Nombor pengoksidaan
–
–
2
berkurang daripada 0 ke -1
Reduction. Oxidation number
decreases from 0 to -1. [2]
MG-10