SOME BASIC CONCEPTS OF CHEMISTRY PART-6

NEET UG, JEE Main Chemistry questions: Online Multiple Choice Questions (MCQs) with answers for NEET and JEE Main aspirants, Chemistry Practice questions, MCQs, Past Year Questions (PYQs), NCERT Questions, Question Bank, Class 11 and Class 12 Questions, NCERT Exemplar Questions ...  

1. The molarity of 20.0 mass % H2SO4 solution of density 11.14 g cm―3 is

a) 2.56 mol dm―3

b)1.56 mol dm―3

c) 1.26 mol dm―3 

d)2.32 mol dm―3

2. How many moles of Fe2+ ions are formed, when excess of iron is treated with 50 mL of 4.0 M HCl under inert atmosphere? Assume no change in volume:

a) 0.4 

b)0.1 

c) 0.2 

d)0.8

3. 100 mL of 0.3 N HCl solution were mixed with 200 mL of 0.6 N H2SO4 solution. The final acidic normality is:

a) 0.9 N 

b)0.6 N 

c) 0.5 N 

d)0.4 N

4. 45 g of acid of mol. wt. 90 neutralized by 200 mL of 5 N caustic potash. The basicity of the acid is:

a) 1 

b)2 

c) 3 

d)4

5. The equivalent weight of KIO3 in the reaction,

2Cr(OH)3 + OH― + KIO3→2CrO2―4 +5H2O + KI is

a) Mol. wt. 

b)Mol. wt./3 

c) Mol. wt./6 

d)Mol. wt./2

6. The sample with largest number of atoms is

a) 1 g of O2(g) 

b)1 g of Ni(s) 

c) 1 g of B(s) 

d)1 g of N2(g)

7. The equation,  2Al(s)(3/2)O2(g)⟶Al2O3(s)shows that:

a) 2 mole of Al reacts with (3/2) mole of O2 to produce (7/2) mole of Al2O3

b)2 g of Al reacts with (3/2) g of O2to produce one mole of Al2O3

c) 2 g of Al reacts with (3/2)litre of O2to produce 1 mole of Al2O3

d)2 mole of Al reacts with (3/2) mole of O2 to produce 1 mole of Al2O3

8. The number of atoms in 3.2 g of oxygen gas are:

a) 6.02 × 1022 

b) 6.02 × 1023 

c) 12.04 × 1022 

d) 12.04 × 1023 

9. The number of atoms in n moles of gas can be given by:

a) n × Av. no. × atomicity 

b) n × Av. no. / atomicity 

c) Av. no. × atomicity / n

d) None of these

10. How many moles of Al2(SO4)3 would be in 50 g of the substance?

a) 0.083 mol 

b) 0.952 mol 

c) 0.481 mol 

d) 0.140 mol

11. The molecular weight of air will be (the components of air given as N2 ―78%,O2 ―21%,Ar ― 09% and CO2 ―0.1%)

a) 18.64 

b) 24.968 

c) 28.964 

d) 29.864

12. 1.520 g of the hydroxide of a metal on ignition gave 0.995 g of oxide. The equivalent weight of metal is:

a) 1.520 

b) 0.995 

c) 19.00 

d) 9.00

13. The hydrated salt Na2SO4 ∙ nH2O, undergoes 55% loss in weight on heating and becomes anhydrous. The value of n will be:

a) 5 

b) 3 

c) 7 

d)10

14. When 100 g of ethylene polymerizes to polyethylene according to the equation, 

    n CH2=CH2    --->  -(CH2-CH)-n

The weight of polyethylene produced will be:

a) n/2 g

b) 100 g 

c) 100 / n

d)100n g

15. Vapour density of a volatile substance is 4 (CH4 = 1). Its molecular weight would be:

a) 8 

b) 2 

c) 64 

d)128

16. Dulong and Petit’s law is valid only for

a) Metals 

b)Non-metals 

c) Gaseous elements 

d)Solid elements

17. The molarity of pure water is:

a) 55.6 

b)50 

c) 100 

d)18

18. A molal solution is one that contains one mole of a solute in:

a) 1000 g of the solvent

b) 1000 mL of the solution

c) One litre of the solvent

d) 22.4 litre of the solution

19. The weight of a substance that displaces 22.4 litre air at NTP is:

a) Mol. wt. 

b) At. wt. 

c) Eq. wt. 

d)All of these

20. The density (in g mL―1) of a 3.60 M H2SO4 solution having 29% by mass of H2SO4 (molar mass 98)will be:

a) 1.45 

b)1.64 

c) 1.88 

d)1.22

Answer Key

1- D , 2- B,  3- C, 4-B , 5-C, 6-C, 7-D, 8-C, 9-A, 10-BD, 

11-C, 12-D, 13-D, 14-B, 15-C, 16-D, 17-A, 18-A, 19-A, 20-D 

READ 👉👉👉 SOME BASIC CONCEPTS OF CHEMISTRY PART-5