2. Calculate the number of particles in-

(i) 8 g of O2 molecules (ii) 2.5 mol of calcium atoms.

3. What is the mass of 2.5 mol of Methane?

4.Find the mass of one molecule of water.

5.Calculate the number of water molecules and number of oxygen and hydrogen atoms

in a drop of water containing 0.03 mol of water.

6. Calculate the actual mass of one atom of carbon if 12 grams of Carbon contain one mole of Carbon.

7. Calculate mass of Nitrogen (N2) which contains same number of molecules as are present in 4.4 grams of Carbon-di-oxide (CO2).

8.Atomic mass of gold is 197 u. How many moles of gold are present in an ornament containing 88.65 grams of gold?

9. How many moles of SO2 have same mass as 3 moles of oxygen?

10. A glass of water contains 5 mol of water. How many molecules of water arepresent?

11. What is the mass of a formula unit of Na + C l - ?

12. How many atoms of Silver are present in a silver wire weighing 5.4 grams?

13. Calculate the ratio of molecules present in 16 g of methane and 16 g of oxygen.

14. Convert into mole. (a) 12 g of oxygen gas (b) 20 g of water (c) 22 g of carbon-dioxide.

15. Determine the number of bromide ion in 0.2 mole of Mg Br2.

**More Problems based on mole concept**

9th Atoms and Molecules -

1. Mole Concept and Problems based on mole concept

2. Numerical Problems based on mole concept 9th Chemistry

3. Numerical based on mole concept by ChemistryAdda