Q1 of 56 Page 83

Mass of one atom of oxygen is:

To calculate the mass of 1 atom of oxygen:

Atomic mass of oxygen = 16

1 mole of atom = 6.022 × 10²³ (Avogadro’s no.)

Mass of 1 oxygen atom = 2.65 × 10²³g

Calculate the number of moles present in:

(i) 92 grams of sodium

(ii) 108 grams of aluminium.

Calculate number of atoms present in:

(i) 0.1 mole of sulphur.

(ii) 2 moles of phosphors.

3.42 of sucrose is dissolved in 18 g of water in a beaker. The number of oxygen atoms in the solution are:

A change in the physical state can be brought about: