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