MCQs on Some Basic Concepts of Chemistry
1. Elements X and Y combine to form two compounds XY and X2Y. Find the atomic weight of X and Y, if the weight of 0.1 moles of XY is 10g and 0.05 moles of X2Y is 9g
(a) 30, 20
(b) 80, 20
(c) 60, 40
(d) 20, 30
Answer:::: (b)
2. Which one will have maximum numbers of water molecules?
(a) 18 molecules of water
(b) 1.8 grams of water
(c) 18 grams of water
(d) 18 moles of water
Answer:::: (d)
3. The number of atoms present in 0.1 moles of a triatomic gas is
(a) 1.806 × 1023
(b) 1.806 × 1022
(c) 3.600 × 1023
(d) 6.026 × 1022
Answer:::: (a)
4. Find the volume of O2 required to burn 1 L of propane completely, measured at 0℃ temperature and 1 atm pressure
(a) 10 L
(b) 7 L
(c) 6 L
(d) 5 L
Answer:::: (d)
5. A gas X has Cp and Cv ratio as 1.4, at NTP 11.2 L of gas X will contain_______ number of atoms
(a) 1.2 × 1023
(b) 3.01 × 1023
(c) 2.01 × 1023
(d) 6.02 × 1023
Answer:::: (d)
6. Which of the species is not paramagnetic?
(a) As+
(b) Cl–
(c) Ne2+
(d) Be+
Answer:::: (b)
7. Pressure has the same dimension as ____________
(a) energy per unit volume
(b) energy
(c) force per unit volume
(d) force
Answer:::: (a)
8. A container has an equal mass of H2, O2 and CH4 at 27℃, the ratio of their volume is
(a) 16:8:1
(b) 8:1:2
(c) 16:1:2
(d) 8:16:1
Answer:::: (c)
9. There are two chlorides of sulphur S2Cl2 and SCl2. What is the equivalent mass of S in SCl2
(a) 64.8 g/mole
(b) 32 g/mole
(c) 16 g/mole
(d) 8 g/mole
Answer:::: (c)
10. Boron exists as two stable isotopes; 10B(19%) and 11B(81%). Find out the average atomic weight of boron in the periodic table
(a) 10.0
(b) 11.2
(c) 10.2
(d) 10.8
Answer:::: (d)
11. The mass of carbon-12 atom considered in the definition of a mole is
(a) 0.12g
(b) 0.012 kg
(c) 120 mg
(d) None of these
Answer:::: (b)
12. Which of the following is a pair of physical and chemical property respectively of a substance
(a) density and acidity
(b) basicity and colour
(c) colour and density
(d) acidity and combustibility
Answer:::: (a)
13. The normality of 0.3M phosphorous acid is
(a) 0.9
(b) 0.1
(c) 0.6
(d) 0.3
Answer:::: (c)
14. 3g of an oxide of a metal is converted into chloride and it yielded 5g of chloride. Find the equivalent weight of the metal
(a) 20
(b) 12
(c) 3.325
(d) 33.25
Answer:::: (d)
15. 0.32 gm of a metal on treatment with an acid gave 112mL of hydrogen at STP. Calculate the equivalent weight of the metal.
(a) 24
(b) 11.2
(c) 32
(d) 58
Answer:::: (c)
16. Which of the following is not a homogenous mixture?
(a) Brass
(b) Air
(c) Smoke
(d) Aqueous solution of sugar
Answer:::: (c)
