Chemistry - SI Units Significant Figures Equivalent Mass Atomic Mass Mole Concept and Chemical Calculations
Exam Duration: 45 Mins Total Questions : 30
M is molecular mass of KMnO4. When KMnO4 is changed to K2 MnO4 the equivalent mass of KMnO4 is
- (a)
M
- (b)
M/3
- (c)
M/5
- (d)
M/7
A saturated solution of potassium nitrate contains 52.4% of the salt at \({ 65 }^{ \circ }\); the solubility coefficient of the salt at this temperature is
- (a)
52.4
- (b)
66.3
- (c)
110
- (d)
114
50 ml of 0.3 N H2SO4 and 100 ml of .15 N HNO3 were mixed together; the normality of resultant solution is
- (a)
0.1
- (b)
0.2
- (c)
0.3
- (d)
0.5
2.76 g of silver carbonate on being heated strongly yields a residue which weighs
- (a)
2.76 g
- (b)
2.48 g
- (c)
2.32 g
- (d)
2.16 g
With how much of oxygen 27 g of Al reacts completely?
- (a)
16 g
- (b)
24 g
- (c)
32 g
- (d)
48 g
How many grams of Cu (at. mass 64) will be displaced when 27 g of Al (at . mas 27). are added to excess of cupric sulphate solution?
- (a)
64
- (b)
96
- (c)
104
- (d)
108
What weight of the sample should be taken so that each 20 mg of AgCl obtained in gravimetric determination of Ag shall correspond to 2% of silver in original sample?
- (a)
.2464
- (b)
.2494
- (c)
.7526
- (d)
.7594
The atomic weight and equivalent weight of a metal are 13.5 and 4.5 respectively; the metal forms volatile chloride the v.d. of which would be
- (a)
30
- (b)
40
- (c)
50
- (d)
60
A metal is burnt in O2; all the products of the combustion are weighed. It is found that the weight of the metal seems to have increased by 24%. The at. wt. of metal would be
- (a)
24
- (b)
27
- (c)
33.34
- (d)
None of these
2N - HCl will have tha same molar concentration as
- (a)
0.5 N H2SO4
- (b)
2.0 N H2SO4
- (c)
1.0 N H2SO4
- (d)
4.0 N H2SO4
The molecular weight of KMnO4 is 158. The equivalent weight of KMnO4 in acidic and neutral medium respectively are
- (a)
158, 158
- (b)
31.6, 31.6
- (c)
31.6, 52.6
- (d)
52.6, 52.6
Which one of the following is not related correctly in SI units?
- (a)
1.35 mm = 1.35 x 10-3 m
- (b)
6.45 m L = 6.45 x 10-3 L
- (c)
48\(\mu g\) = 4.8 x 10-5 g
- (d)
0.426 inch = 1.08 x 10-3 m
Vanadium metal is added to steel to impart strangth. The density of Vanadium is 5.96 g cm-3. The value of density of Vanadium in S.I. unit would be
- (a)
5.96 x 103 kg m-3
- (b)
5.96 x 102 kg m-3
- (c)
5.96 x 104 kg m-3
- (d)
5.96 x 10-3 kg m-3
A solution is prepared by dissolving 18.25 g of NaOH in distilled water to give 200 cm3 of solution. The molarity of NaOH solution is
- (a)
1.14
- (b)
2.28
- (c)
4.56
- (d)
None of these
What is the mass in grams of 0.25 mol copper?
Cu = 63.5 a.m.u.
- (a)
8
- (b)
16
- (c)
24
- (d)
32
How many oxygen atoms are there in 6.025 g. Ba3(PO4)2 ? Ba = 137.5, P = 31, O =16
- (a)
9.6 x1022
- (b)
4.8 x1022
- (c)
2.4 x1022
- (d)
1.2 x1022
How many molecules of benzene are there in 1 litre of benzene? Specific gravity of benzene is 0.88.
- (a)
3.4 x 1024
- (b)
6,8 x 1024
- (c)
1.7 x 1024
- (d)
13.6 x 1024
The volume of a drop of water is 0.04 cm3. How many H2O molecules are there in drop of water? Density of water = 1.0 g cm-3
- (a)
1.3 x 1021
- (b)
5.2 x 1021
- (c)
3.9 x 1021
- (d)
2.6 x 1021
One mole of CO2 contains
- (a)
6.023 x 1023 atoms of carbon
- (b)
3 g atoms of CO2
- (c)
18.1 x 1023 molecules of CO2
- (d)
6.023 x 1023 atoms of oxygen
1.081 g of Cu displaces 3.670 g Ag from a solution of AgNO3. Find the eq. wt. of Cu, that of Ag being 107.88.
- (a)
30.71
- (b)
31.77
- (c)
29.72
- (d)
40.71
One mole of CO2 contains
- (a)
3 g atoms of CO2
- (b)
18.1 x 1023 molecules of CO2
- (c)
6.02 x 1023 atoms of oxygen
- (d)
6.02 x 1023 atoms of carbon
Volume of a gas at NTP is 1.12 x 10-7 cc. Calculate the number of molecules in it.
- (a)
3.01 x 1020
- (b)
3.01 x 1012
- (c)
30.1 x 1023
- (d)
3.01 x 1024
4.4 g of unknown gas occupies2.24 L of volume at standard temperature and pressure. The gas may be
- (a)
Carbon dioxide
- (b)
Carbon monoxide
- (c)
Oxygen
- (d)
Sulphur dioxide
The number of moles of oxygen in 1L of air containing 21 % oxygen by volume, in standrad conditions, is
- (a)
0.186 mol
- (b)
0.21 mol
- (c)
2.10 mol
- (d)
0.0093 mol
The hydrogen phosphate of certain metal has formula MHPO4. The formula of metal chloride would be
- (a)
MCl
- (b)
MCl2
- (c)
M2Cl2
- (d)
MCl3
One mole of CO2 contains
- (a)
6.02 x 1023 atoms of C
- (b)
6.02 x 1023 atoms of O
- (c)
18.1 x 1023 molecules of CO2
- (d)
3 grams of carbon
Two elements, X ( at. mass 75) and Y ( at. mass 16) combine to give a compound having 78.8% X. The formula of the compound is :
- (a)
XY
- (b)
X2Y
- (c)
X2Y2
- (d)
X2Y3
Avogadro number is
- (a)
number of atoms in one gram of the element
- (b)
number of millilitres which one mole of a gaseous substance occupies at NTP
- (c)
number of molecules present in one gram molecular mass of a substance
- (d)
All are correct
19.7 kg of gold was recovered from a smuggler. How many atoms of gold were recovered ? (Au = 197)
- (a)
100
- (b)
6.02 x 1023
- (c)
6.02 x 1024
- (d)
6.02 x 1025
12 g of Mg (at. mass 24 ) will react completely with acid to give
- (a)
One mol of H2
- (b)
1/2 mol of H2
- (c)
2/3 mol of O2
- (d)
both 1/2 mol of H2 and 1/2 mol of O2
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