Mole Concept Multiple Choice Questions and Answers

11. 5.6 litres of gas at N.T.P are found to have a mass of 11 g. The molecular mass of the gas is

1. 22
2. 44
3. 88
4. 32

12. 5.6 litres of oxygen at NTP is equivalent of

1. 1 mole
2. 1/2 mole
3. 1/4 Mole
4. 1/8 mole

13. 6.02×10²² molecules of N₂ at NTP will occupy a volume of

1. 22.4 litres
2. 2.24 litres
3. 6.02 litres
4. 6.02 mL

14. A sample of phosphrous trichloride(PCl₃) contains 1 .4 moles of the substance. how many atoms are there is the sample ?

1. 5.6
2. 4
3. 8.431× 10²³
4. 3.372× 10²⁴

15. A symbol not only represents the name of the element but also represents

1. its atomic no.
2. 1 gm-atom
3. its atomicity
4. Reactivity.

16. Atomic mass of an elements is

1. the actual mass of one atom of the element
2. the relative mass of an atom of the element
3. the average relative mass of different atoms of the element
4. much different from the mass number of the element.

17. Avogadros number represents the number of atoms in

1. 12g of C¹²
2. 320g of sulphur
3. 32g of oxygen
4. 12.7g of iodine

18. How many grams are contained in 1 gram-atom of Na?

1. 13g
2. 23g
3. 1 g
4. 1/23g

19. I mole of a compuund contain 1 mole of C and 2 moles of O. The molecular weight of the compound is

1. 3
2. 12
3. 32
4. 44

20. Mass of a mole of electrons is

1. 0.20mg
2. 0.02mg
3. 0.55mg
4. 1.00mg