There is a large temperature interval between the melting point and the boiling point of a metal because?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(D)
600 k
5
Which of the following is a measure of the average kinetic energy of the molecules of a substance?
Απάντηση
(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)
Απάντηση
(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?
Απάντηση
(D)
number of collisions between the gas molecules and the walls of the container
8
The nucleus of the isotope tritium, contains?
Απάντηση
(C)
two neutrons and one proton
9
How many lone pairs of electron are there on the central atom of the H2O molecules?
Απάντηση
(B)
2
10
147N + X → 178O + 11 H. In the above reaction, X is a?
Απάντηση
(B)
helium atom
11
The pollutants that are likely to be present in an industrial environment are?
Απάντηση
(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?
Απάντηση
(D)
S
13
Which of the following gases dissolves in water vapour to produce acid rain during rainfall?
Απάντηση
(D)
Sulphur (IV) oxide
14
Water for town supply is chlorinated to make it free from?
Απάντηση
(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
Απάντηση
(A)
I, II, III and IV
16
An emulsion paint consists of ?
Απάντηση
(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?
Απάντηση
(B)
6.3 x 10-11
18
Arrange HCI, CH3COOH, C6H5CH3 in order of increasing conductivity.
Απάντηση
(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)
Απάντηση
(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 ?
Απάντηση
(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.
Απάντηση
(B)
5.4
22
S2O2-3 + I2 → S2O62- + 2I-. In reaction above, the oxidizing agent is?
Απάντηση
(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?
Απάντηση
(C)
-2, 1, 0
24
In which of the following is the entropy change positive?
Απάντηση
(A)
H2O(I) → H2O(g)
25
In what way is equilibrium constant for the forward reaction related to that of the reversed reaction?
Απάντηση
(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?
Απάντηση
(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?
Απάντηση
(C)
(R)m (S)n / (p)x (Q)y
28
Which of these statements is TRUE about carbon (IV) oxide?
Απάντηση
(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.
Απάντηση
(C)
i and iii
30
Which of the following oxides of nitrogen is unstable in air?
Απάντηση
(B)
NO
31
The gas formed when ammonium trioxonitrate (V) is heated with sodium hydroxide is?
Απάντηση
(D)
ammonium
32
The gas formed when ammonium trioxonitrate (V) is heated with sodium hydroxide is?
Απάντηση
(D)
ammonia
33
Safety matches contain sulphur and the following except?
Απάντηση
(A)
sodium chloride
34
Addition of an aqueous solution of a salt gives a white precipitate. The salt is likely to be a?
Απάντηση
(B)
carbonate
35
Sodium hydroxide solution can be conveniently stored in a container made of?
Απάντηση
(D)
copper
36
Which of the following is NOT used as a raw material in the Solvay process?
Απάντηση
(D)
Sodium trioxocarbonate (IV)
37
Duralumin consists of aluminium, copper, ?
Απάντηση
(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?
Απάντηση
(B)
slaking
39
The carbon atoms in ethene are?
Απάντηση
(C)
sp2 hybridized
40
Which of the following compounds reacts with sodium metal as well as silver and copper salts ?
Απάντηση
(C)
CH3C Ξ CH
41
Which of the following are isomers?
Απάντηση
(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?
Απάντηση
(D)
carboxyl group
43
An organic compound containing 40.1% carbon and 6.6% hydrogen has an empirical formula of?
Απάντηση
(C)
CH2O
44
The characteristics reaction of carbonyl compounds is?
Απάντηση
(C)
addition
45
Alkanals can be differentiated from alkanones by reaction with?
Απάντηση
(D)
Tollen's reagent
46
An example of a polysaccharides is?
Απάντηση
(D)
starch
47
In the experiment above. Z can be
Απάντηση
(C)
a solution of sodium trioxonitrate (V) and ammonium chloride
48
Which of the following compounds is a secondary alkanol?
Απάντηση
(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?
Απάντηση
(D)
600k
50
Which of the following is a measure of the average kinetic energy of the molecules of a substance?
