What is the mass of:
(a) 0.2 mole of oxygen atoms?
Answer
We know that,
Number of moles of a substance = Given mass of the substance / Molar mass of the substance
Therefore,
Mass of the substance = Number of moles x Molar mass of the substance
(a) 0.2 mole of oxygen atoms
Given mass of O = m = ?
Molar Mass of O = M = 16g
Number of moles = n = 0.2 = 2/10
We know that,
Mass of the substance = Number of moles x Molar of the substance
m = n x M
= (2 /10) x 16
= 32 /10
= 3.2g