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Free download in PDF Some Basic Concepts of Chemistry Objective Type Questions and Answers for competitive exams. These short objective type questions with answers are very important for Board exams as well as competitive exams like NEET, AIIMS, JIPMER, IIT-JEE etc. These short solved questions or quizzes are provided by Gkseries.
(21)
What volume 0.8 M solution contains 0.1 mole of solute?
[A]
100 mL
[B]
125 mL
[C]
500 mL
[D]
None of these
(22)
Naturally occurring thallium consists of two stable isotopes, Tl-203 and Tl-205 (atomic mass = 203.0 and 205.0, respectively) and has an average atomic mass of 204.4. What is percentage of Tl – 205?
[A]
14.0%
[B]
30.0%
[C]
70.0%
[D]
None of these
(23)
Total mass of 1 mole of CO2 + 10 g mole of O2 + 5 g molecule of SO3 + 5 g atom of Na + 10 g of SO3 + 5 g of Na atom
[A]
764 g
[B]
879 g
[C]
894 g
[D]
None of these
(24)
Four containers of 2 L capacity contains dinitrogen as described below. Which one contains maximum number of molecules?
[A]
2.5 g molecule of N2
[B]
4 g atom of nitrogen
[C]
82 g of dinitrogen
[D]
None of the above
Answer: 82 g of dinitrogen
(25)
Which of the following represents 1 g mole of the substance
[A]
6.02 1023 molecules of NH3
[B]
4 g of He
[C]
56 g of CaO
[D]
None of these
(26)
The maximum volume of STP is occupied by
[A]
1 g molecule of CO2
[B]
1 g of CO2 of molecule
[C]
44.5 g of CO2
[D]
None Of The Above
(27)
one gram atom of Nitrogen atom corresponds to
[A]
NA molecules of N2
[B]
11.2 L of N2 at STP
[C]
14 g of N2
[D]
22.4 L of N2 at STP
Answer: 11.2 L of N2 at STP
(28)
The number of moles of oxygen in 1 L of air containing 21% oxygen by volume, in standard conditions, is
[A]
0.186 mol
[B]
0.21 mol
[C]
0.0093 mol
[D]
None of these
(29)
4 g of an unknown gas occupies 2.24 L of volume at Standard temperature and pressure. The gas may be
[A]
Carbon dioxide
[B]
Carbon monoxide
[C]
Oxygen
[D]
Sulphur dioxide
(30)
In a mole of water vapours at STP, the volume actually occupied or taken by the molecules (i.e., Avogadro’s No. x volume of one molecule) is
[A]
Zero
[B]
Less than 1% of 22.4 L
[C]
About 10% of the volume of container
[D]
1% to 2% of 22.4 L
Answer: 1% to 2% of 22.4 L
31
The mass of 112 cm3 of CH4 gas at STP is
[A]
0.16 g
[B]
0.8 g
[C]
0.08 g
[D]
1.6 g
32
32 g O2, 2 g H2 and 28 g N2 at STP occupy separately a volume of
[A]
1 L
[B]
2 L
[C]
22.4 L
[D]
None of the above
33
Which of the following contains maximum number of molecules?
[A]
100 cc of CO2 at STP
[B]
150 cc of N2 at STP
[C]
50 cc of SO2 at STP
[D]
150 cc of O2 at STP
Answer: 50 cc of SO2 at STP
34
The maximum number of molecules is present in
[A]
10 g of O2 gas
[B]
15 L of H2 gas at STP
[C]
5 L of N2 gas at STP
[D]
none of these
Answer: 15 L of H2 gas at STP
35
An alkaloid contains 17.28% of nitrogen and its molecular mass is 162. The number of nitrogen atoms present in one molecule of alkaloid is:
[A]
Five
[B]
Four
[C]
Three
[D]
Two
36
How many atoms are contained in one mole of sucrose (C12H22OH)?
[A]
45 6.02 1023 atoms/mole
[B]
5 6.62 1023 atoms/mole
[C]
5 6.02 1023 atoms/mole
[D]
None of these
Answer: 45 6.02 1023 atoms/mole
37
The largest number of molecules is in
[A]
34 g of water
[B]
28 g of CO2
[C]
46 g of CH3COH
[D]
54 g of N2O5
38
One mole of CO2 contains
[A]
6.02 1023 atoms of C
[B]
6.02 1023 atoms of O
[C]
18.1 1023 molecules of CO2
[D]
3 gram of carbon
Answer: 6.02 1023 atoms of C
39
How many molecules are present in one gram of hydrogen?
[A]
6.02 1023
[B]
3.01 1023
[C]
2.5 1023
[D]
1.5 1023
40
0.2 mole of HCl and 0.2 mole of barium chloride were dissolved in water to produce a 500 mL solution. The molarity of the Cl– ions is:
[A]
0.06 M
[B]
0.09 M
[C]
1.2 M
[D]
None Of The Above
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