IISER Chemistry - S.I. Units, Significant Figures, Equivalent Mass, Atomic Mass, Mole Concept And Chemical Calculations
Exam Duration: 45 Mins Total Questions : 30
0.5 mole of Bacl2 is mixed with 0.2 mole of Na3PO4, the maximum number of moles of Ba3(PO4)2 that can be formed is
- (a)
0.01
- (b)
0.10
- (c)
0.30
- (d)
0.50
50 ml of LiOH can completely neutralise 25 ml of 2M phoshoric acid. The molarity of LiOH is
- (a)
1
- (b)
2
- (c)
3
- (d)
5
When the same amount of the zinc is heated separately with excess of H2SO4 and excess of NaOH the ratio of the hydrogen gas evolved is
- (a)
1:1
- (b)
1:2
- (c)
2:3
- (d)
3:4
ZnSO4 is isomorphus with MgSO4.7H2O. If the eq. wt. of Zn is 32.5 then its at. wt. would be
- (a)
32.5
- (b)
65
- (c)
130
- (d)
140
Number of moles of KClO3 required to complete the reaction \({ KClO }_{ 3 }\quad +\quad { C }_{ 12 }{ H }_{ 22 }{ O }_{ 11 }\rightarrow \quad KCl\quad +{ CO }_{ 2 }+{ H }_{ 2 }O\) will be
- (a)
2
- (b)
6
- (c)
8
- (d)
16
Chloride of an element contains 92.21 % of chloride by weight. Its v.d. is 77. The at. wt. of the element is
- (a)
12
- (b)
24
- (c)
36
- (d)
48
Chloride of a metal M contains 31% chlorine. This chloride is isomorphus with KCl. The calculated at. wt. of the metal would be
- (a)
39
- (b)
62
- (c)
82.83
- (d)
96
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
9.5 g of dehydrate castor oil required 8.5 ml of N/10 KOH solution for neutralisation of free acid present. The acid value is
- (a)
4.01
- (b)
5.01
- (c)
6.01
- (d)
7.01
1.55 g of an oil saponified with 28 ml of N/2 alcoholic KOH. The mix requires 15 ml of N/2 HCl. The saponification value of oil is
- (a)
188.7
- (b)
178.7
- (c)
198.7
- (d)
200.7
The molecular mass of magnesium carbonate is 84. The volume (in litre) of carbon dioxide obtained at STP on heating 4.2 g of magnasium carbonate would be
- (a)
22.40
- (b)
11.20
- (c)
1.12
- (d)
2.224
The reactant which is completely consumed during the reaction is called
- (a)
active reactant
- (b)
active product
- (c)
limiting reagent
- (d)
limiting product
The number of grams of oxygen in 0.1 mole of Na2CO3.10H2O is
- (a)
16 g
- (b)
20.8 g
- (c)
28 g
- (d)
32 g
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 of one ammonia molecule? N = 14, H = 1
- (a)
1.4 x 10-23 g
- (b)
2.8 x 10-23 g
- (c)
5.6 x 10-23 g
- (d)
7.0 x 10-23 g
For the preparation of 0.6 mol of K2Cr2O7, the number of potassium atoms required are
- (a)
2.0 x 1023
- (b)
7.22 x 1023
- (c)
6.02 x 1023
- (d)
3.01 x 1024
The number of moles of CO2 which contain 8.0 g of oxygen are
- (a)
0.25
- (b)
0.50
- (c)
1.0
- (d)
1.50
27 g of Al will react completely with
- (a)
24 g of oxygen
- (b)
32 g of oxygen
- (c)
16 g of oxygen
- (d)
8 g 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
An organic compound on analysis was found to contain 0.032% of sulphur. It was also found that oe molecule of the compound contains one atom of sulphur. The molecular weight of the compound will be
- (a)
10
- (b)
32
- (c)
100000
- (d)
100
The maximum amount of BaSO4 precipitated on mixing BaCl2 (0.5 M) with H2SO4 (1 M) will correspond to
- (a)
0.5 M
- (b)
1.0 M
- (c)
1.5 M
- (d)
2.0 M
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
The number of moles of sodium oxide in 620 g of it:
- (a)
1 mol
- (b)
10 moles
- (c)
18 moles
- (d)
100 moles
The volume of 1.0 g of hydrogen in litres at N.T.P. is:
- (a)
2.24
- (b)
22.4
- (c)
1.12
- (d)
11.2
Which of the following has the largest number of atoms?
- (a)
0.5 g atoms of Cu
- (b)
0.635 g of Cu
- (c)
0.25 moles of Cu atoms
- (d)
1 g of Cu
The number of gram- molecules of oxygen in 6.02 x 1024 CO molecules is :
- (a)
10 g-molecules
- (b)
5 g-molecules
- (c)
1 g-molecule
- (d)
0.5 g-molecule
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
If 1021 molecules are removed from 200 mg of CO2, then the number of moles of CO2 left are :
- (a)
2.88 x 10-3
- (b)
1.66 x 10-3
- (c)
4.54 x 10-3
- (d)
1.66 x 10-3
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