JAWAPAN PENILAIAN KURIKULUM 2011

Kimia

Form 5
Objective
1 A 2 B 3 A 4 C 5 B 6 B 7 A 8 C 9 A 10 B
11 C 12 B 13 C 14 C 15 C 16 C 17 D 18 A 19 A 20 B

1	(a)			Complete set of apparatus and can be used and label	2
	(b)			Zn + H2SO4 → ZnSO4 + H2	1
	(c)			Experiment I =   0.167 cm3 s-1 Experiment II =  0.267 cm3 s-1	1 1
	(d)			Number of moles of H2SO4 =  = 0.002 mol 1 mol of H2SO4 produce 1 mol of H2 0.002 mol of H2SO4 produce 0.002 mol of H2 Maximum volume of H2 = 0.002 x 24 000 = 48 cm3	1   1
	(e)			·         The rate of reaction in experiment II is higher than that of experiment I. ·         Copper(II) sulphate solution lowers the activation energy of the reaction in experiment II. ·         The frequency of effective collisions between hydrogen ions and zinc atoms increases in experiment II.	1 1   1
	3 (a) 1.      Oxidation - increase in oxidation number 2.      Reduction – decrease in oxidation number 1 1 (b)(i) 1.      Fe+2  →  Fe+3  +  e 2.      Br2  +  2e  →  2Br – 3.      Iron(II) ions lose electrons to become iron(III) ions. Iron(II) ions are oxidised 4.      Bromine molecules gain electrons to form bromide ions. Bromine molecules are reduced (a: any suitable reducing agent) 1.      Fe+3  +  e  →  Fe+2  2.      Zn  →  Zn+2  +  2e 3.      Iron(III) ions gain electrons to become iron(II) ions. Iron(III) ions are reduced 4.      Zinc atoms lose electrons to form zinc ions. Zinc atoms are oxidised (a: any suitable reducing agent) 1 1 1 1 1 1 1 1