There is a large temperature interval between the melting point and the boiling point of a metal because?
Răspuns
(C)
melting does not break the metalic bond but boiling does
2
How many moles of (H+) are there in 1 dm3 of 0.5 M solution of H2SO4?
Răspuns
(B)
1.0 moles
3
wH2SO4 + xAI(OH)3 → yH2O + = zAI2(SO4)3. The respective values of w.x.y and z in the equation above are?
Răspuns
(C)
3,2,6 and 1
4
A given mass of gas occupies 2 dm3 at 300k. At what temperature will its volume be doubled keeping the pressure constant?
Răspuns
(D)
600 k
5
Which of the following is a measure of the average kinetic energy of the molecules of a substance?
Răspuns
(D)
Temperature
6
If 100 cm3 of oxygen pass through a porous plug in 50 seconds, the time taken for the same volume of hydrogen to pass through the same porous plug is?
(O = 16, H = 1)
Răspuns
(B)
12.5 s
7
An increase in temperature causes an increase in pressure of a gas in a fixed volume due to an increase in the?
Răspuns
(D)
number of collisions between the gas molecules and the walls of the container
8
The nucleus of the isotope tritium, contains?
Răspuns
(C)
two neutrons and one proton
9
How many lone pairs of electron are there on the central atom of the H2O molecules?
Răspuns
(B)
2
10
147N + X → 178O + 11 H. In the above reaction, X is a?
Răspuns
(B)
helium atom
11
The pollutants that are likely to be present in an industrial environment are?
Răspuns
(A)
H2S,SO2 and oxides of nitrogen
12
Four elements P,Q,R and S have 1,2,3, and 7 electrons in their outermost shells respectively. The element which is unlikely to be a metal is?
Răspuns
(D)
S
13
Which of the following gases dissolves in water vapour to produce acid rain during rainfall?
Răspuns
(D)
Sulphur (IV) oxide
14
Water for town supply is chlorinated to make it free from?
Răspuns
(B)
bacteria
15
On which of the following is the solubility of a gaseous substance dependent? I. Nature of solvent II. Nature of solute III. Temperature IV. Pressure
Răspuns
(A)
I, II, III and IV
16
An emulsion paint consists of ?
Răspuns
(B)
liquid particles dispersed in liquid
17
A sample of orange juice is found to have a pH of 3.80. What is he concentration of the hydroxide ion in the juice?
Răspuns
(B)
6.3 x 10-11
18
Arrange HCI, CH3COOH, C6H5CH3 in order of increasing conductivity.
Răspuns
(C)
C6H5CH3, CH3COOH, HCI
19
How many grams of H2SO4 are necessary for the preparation of 0.175 dm3 of M 6.00 M H2SO4?
(S = 32.06, O = 16.00 H = 1.00)
Răspuns
(B)
103.0 g
20
Copper (II) tetraoxosulphate (VI) solution is electrolyzed using carbon electrodes. Which of the following are produced at the anode and cathode respectively ?
Răspuns
(B)
Oxygen and copper
21
Calculate the mass, in kilograms, of magnesium produced by the electrolysis of magnesium (II) chloride in a cell operating for 24 hours at 500 amperes.
Răspuns
(B)
5.4
22
S2O2-3 + I2 → S2O62- + 2I-. In reaction above, the oxidizing agent is?
Răspuns
(B)
I2
23
\(MnO_2 + 2CI^- + 4H^+ → Mn^{2+} + CI_2 + 2H_2O\).
The changes in oxidation numbers when the manganese, chloride, and hydrogen ions react according to the above equation are respectively?
Răspuns
(C)
-2, 1, 0
24
In which of the following is the entropy change positive?
Răspuns
(A)
H2O(I) → H2O(g)
25
In what way is equilibrium constant for the forward reaction related to that of the reversed reaction?
Răspuns
(B)
The product of the two is expected to be one
26
Which of the following equilibria shows little or no net reaction when the volume of the system is decreased?
Răspuns
(D)
ZnO(s) + CO2(g) ≈ ZnCO3(g)
27
For a general equation of the nature xP + yQ ≈ mR + nS, the expression for the equilibrium constant is?
Răspuns
(C)
(R)m (S)n / (p)x (Q)y
28
Which of these statements is TRUE about carbon (IV) oxide?
Răspuns
(C)
It is very soluble in water
29
Which of the following combination of gases is used for metal welding? i. Oxygen and ethyne, ii. Hydrogen and ethyne, iii. Hydrogen and oxygen, iv. Ethyne, hydrogen and oxygen.
Răspuns
(C)
i and iii
30
Which of the following oxides of nitrogen is unstable in air?
Răspuns
(B)
NO
31
The gas formed when ammonium trioxonitrate (V) is heated with sodium hydroxide is?
Răspuns
(D)
ammonium
32
The gas formed when ammonium trioxonitrate (V) is heated with sodium hydroxide is?
Răspuns
(D)
ammonia
33
Safety matches contain sulphur and the following except?
Răspuns
(A)
sodium chloride
34
Addition of an aqueous solution of a salt gives a white precipitate. The salt is likely to be a?
Răspuns
(B)
carbonate
35
Sodium hydroxide solution can be conveniently stored in a container made of?
Răspuns
(D)
copper
36
Which of the following is NOT used as a raw material in the Solvay process?
Răspuns
(D)
Sodium trioxocarbonate (IV)
37
Duralumin consists of aluminium, copper, ?
Răspuns
(D)
manganese and magnesium
38
CaOs + H2O(l) → Ca(OH)2(s) ΔH -65 kj. The process represented by the above equation is known as?
Răspuns
(B)
slaking
39
The carbon atoms in ethene are?
Răspuns
(C)
sp2 hybridized
40
Which of the following compounds reacts with sodium metal as well as silver and copper salts ?
Răspuns
(C)
CH3C Ξ CH
41
Which of the following are isomers?
Răspuns
(A)
Ethanol and dimethyl ether
42
The functional group present in an organic compound which gives bubbles on treatment with a saturated solution of NaHCO3 is?
Răspuns
(D)
carboxyl group
43
An organic compound containing 40.1% carbon and 6.6% hydrogen has an empirical formula of?
Răspuns
(C)
CH2O
44
The characteristics reaction of carbonyl compounds is?
Răspuns
(C)
addition
45
Alkanals can be differentiated from alkanones by reaction with?
Răspuns
(D)
Tollen's reagent
46
An example of a polysaccharides is?
Răspuns
(D)
starch
47
In the experiment above. Z can be
Răspuns
(C)
a solution of sodium trioxonitrate (V) and ammonium chloride
48
Which of the following compounds is a secondary alkanol?
Răspuns
(A)
A
49
A given mass of gas occupies 2 dm2 at 300k. At what temperature will its volume be doubled keeping the pressure constant?
Răspuns
(D)
600k
50
Which of the following is a measure of the average kinetic energy of the molecules of a substance?
