Equilibrium is said to be attained in reversible reaction when
Răspuns
(D)
the rates of the forward and backward reactions are equal
2
An acid present in proteins is
Răspuns
(B)
amino acid
3
The following are uses of sulphur except
Răspuns
(E)
coating of steel to prevent rusting
4
The reaction represented by the equation NaOH(aq) + HCI(aq) → NaCI(aq) + H2O(/)
Răspuns
(B)
is a neutralization
5
Which of the following compound is aromatic?
Răspuns
(A)
Benzene
6
Which of the following does not affect the rate of a chemical reaction?
Răspuns
(C)
The enthalpy change for the reaction
7
Which of the following does not affect the rate of a chemical reaction?
Răspuns
(C)
The enthalpy change for the reaction
8
Given that 32.0g sulphur contains 6.02 x 10 23 sulphur atoms how many atoms are there in 2.70g of aluminium? {Al = 27, S =32}
Răspuns
(C)
6.02 x 1022
9
The empirical formula of hydrocarbon containing 0. 12 mole of carbon and 0.36 mole of hydrogen is
Răspuns
(B)
CH3
10
A salt which loses mass when exposed to air is
Răspuns
(C)
efflorescent
11
Detergents are better than soaps for laundry because
Răspuns
(C)
scum is precipitated when soaps are used with hard water but not with stergents
12
Which of the following is used as an anaesthetic?
Răspuns
(B)
CHCI3
13
Which of the following types of hybridization gives rise to tetrahedral molecules?
Răspuns
(C)
sp3
14
Which of the following is a neutral oxide?
Răspuns
(E)
Nitrogen oxide
15
Which of the following statements is not correct?
Răspuns
(C)
Chlorine exhibits allotopy
16
The following are uses of radioactive isotopes except for
Răspuns
(E)
determining equilibrum positions
17
The main characteristic feature of transition metals is that they
Răspuns
(D)
have variable oxidation states
18
The following are heavy chemicals except
Răspuns
(E)
dyes
19
What quantity of silver is deposited when 96500C of electricity is passed through a solution containing silver ions? (Ag = 108, 1F = 96500C)
Răspuns
(E)
108g
20
Bubbling of carbon (IV)oxide into calcium hydroxide solution results in the formation of
Răspuns
(A)
CaCO3
21
Which of the following is not decomposed by heat?
Răspuns
(D)
Na2CO3
22
Which of the following is not true of the rusting of iron?
Răspuns
(A)
Rusting is a reduction process
23
Which of the following is not true of the rusting of iron?
Răspuns
(A)
Rusting is a reduction process
24
What volume of oxygen will be left unreacted when a mixture of 100cm3 of hydrogen and 200cm,sup>3,/sup> of oxygen are exploded in a eudiometer?
Răspuns
(C)
150cm3
25
How many isomers can be obtained from C4H10?
Răspuns
(C)
2
26
Water gas is a mixture of?
Răspuns
(E)
CO and H2
27
Which of the following metals cannot extracted from its ore by using carbon (ll) oxide as the reducing agent?
Răspuns
(C)
Al
28
Which of the following is not a naturally occurring iron ore?
Răspuns
(A)
FeCl2
29
Which of the following equations represents the reaction of chlorine with hot concentrated sodium hydroxide solution?
Răspuns
(C)
6NaOH + 3CI2 → NaCIO3 + 5NaCI + 3H2O
30
Aqueous sodium trioxocarbonate (IV) solution is alkaline because
Răspuns
(E)
sodium triocarbonate (IV) is hydrolysed in water
31
Which of the following correctly explains why iodine crystals change directly into the gaseous state when heated?
Răspuns
(C)
lodine molecules are held together by weak forces
32
Which of the following is a waste product in the Solvary Process for the manufacture of sodium trioxocarbonate (IV)?
Răspuns
(E)
Calcium chloride
33
When copper (ll) chloride solution is treated with excess aqueous ammonia, a deep blue solution results This is due to the presence of
Răspuns
(E)
[cU(NH3)4] ions
34
The complex salt formed when aluminium dissolves in sodium hydroxide solution is
Răspuns
(E)
NaAI(OH)4
35
The reaction represented by the equation C(s) + H2O(l) → CO(s) + H 2(s) was carried out at 27oC if the enthalpy change was + 4500 J and the entropy change was + 12J, what was the free energy change? (∆G = ∆H - T∆S)
