OBJECTIVE LEVEL – I
1. Potassium combines with two isotopes of chlorine (35Cl and 37Cl) respectively to form two samples of KCl. Their formation follows the law of:
(A) constant proportions (B) multiple proportions
(C) reciprocal proportions (D) none of these
2. H2S contains 5.88% hydrogen, H2O contains 11.11% hydrogen while SO2 contains 50% sulphur. These figures illustrate the law of:
(A) conservation of mass (B) constant proportions
(C) multiple proportions (D) reciprocal proportions
3. The best standard of atomic mass is:
(A) carbon-12 (B) oxygen-16
(C) hydrogen-1.008 (D) chlorine-35.5
4. The chemical formula of a particular compound represents:
(A) the size of its molecule
(B) the shape of its molecule
(C) the total number of atoms in a molecule
(D) the number of different types of atoms in a molecule
5. Two containers P and Q of equal volume (1 litre each) contain 6 g of O2 and SO2 respectively at 300 K and 1 atmosphere. Then
(A) Number of molecules in P is less than that in Q
(B) Number of molecules in Q is less than that in P
(C) Number of molecules in P and Q are same
(D) Either (A) or (B)
6. The product of atomic mass and specific heat of any element is a constant, approximately 6.4. This is known as:
(A) Dalton’s law (B) Avogadro’s law
(C) Gay-Lussac law (D) Dulong Petit’s law
7. 250 ml of a sodium carbonate solution contains 2.65 grams of Na2CO3. If 10 ml of this solution is diluted to one litre, what is the concentration of the resultant solution? (mol wt. of Na2CO3 = 106)
(A) 0.1 M (B) 0.001M
(C) 0.01 M (D) 10-4 M
8. 7.5 grams of a gas occupy 5.6 litres of volume at STP. The gas is
(A) NO (B) N2O
(C) CO (D) CO2
9. The weight of a molecule of the compound C60H122 is
(A) 1.4 ´ 10-21 g (B) 1.09 ´ 10-21 g
(C) 5.025 ´ 1023 g (D) 16.023 ´ 1023 g
10. 1.0 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 g-atoms of CO2
11. The number of atoms in 1.4 g nitrogen gas is:
(A) 6.02 × 1022 (B) 3.01 × 1022
(C) 1.20 × 1023 (D) 6.02 × 1023
12. Which of the following has the smallest number of molecules?
(A) 22.4 × 103 ml of CO2 gas (B) 22 g of CO2 gas
(C) 11.2 litre of CO2 gas (D) 0.1 mole of CO2 gas
13. The number of grams of H2SO4 present in 0.25 mole of H2SO4 is
(A) 0.245 (B) 2.45
(C) 24.5 (D) 49.0
14. At NTP 1.0 g hydrogen has volume in litre:
(A) 1.12 (B) 22.4
(C) 2.24 (D) 11.2
15. 19.7 kg of gold was recovered from a smuggler. The atoms of gold recovered are: (Au = 197)
(A) 100 (B) 6.02 × 1023
(C) 6.02 × 1024 (D) 6.02 × 1025
16. The molecular mass of CO2 is 44 amu and Avogadro’s number is 6.02 × 1023. Therefore, the mass of one molecule of CO2 is:
(A) 7.31 × 10–23 (B) 3.65 × 10–23
(C) 1.01 × 10–23 (D) 2.01 × 10–23
17. The number of moles of H2 in 0.224 litre of hydrogen gas at NTP is:
(A) 1 (B) 0.1
(C) 0.01 (D) 0.001
18. Irrespective of the source, pure sample of water always yields 88.89% mass of oxygen and 11.11% mass of hydrogen. This is explained by the law of:
(A) conservation of mass (B) constant composition
(C) multiple proportion (D) constant volume
19. Given the numbers: 161 cm; 0.161 cm; 0.0161 cm. The number of significant figure for three numbers is:
(A) 3, 4, 5 (B) 3, 3, 3
(C) 3, 3, 4 (D) 3, 4, 4
20. Which one of the following law directly explains the law of conservation of mass?
(A) Hund’s rule (B) Dalton’s law
(C) Avogadro’s law (D) Berzelius hypothesis
No comments:
Post a Comment