Convert into mole.
(a) 12 g of oxygen gas
(b) 20 g of water
(c) 22 g of carbon dioxide.
Answer
We know that,
Number of moles of a substance = Given mass of the substance / Molar mass of the substance
(a) 12 g of oxygen gas
Given mass of O 2 = m = 12g
Molar Mass of O 2 = M = 32g
We know that,
Number of moles of a substance = Given mass of the substance / Molar mass of the substance
= m/M
= 12g / 32g
= 6 /16 moles
= ⅜ moles
(b) 20 g of water
Given mass of H 2 O = m = 20g
Molar Mass of H 2 O = M = 18g
We know that,
Number of moles of a substance = Given mass of the substance / Molar mass of the substance
= m/M
= 20g/18g
= 10/9 moles
(c) 22 g of carbon dioxide
Given mass of CO 2 = m = 22g
Molar Mass of CO 2 = M = 44g
We know that,
Number of moles of a substance = Given mass of the substance / Molar mass of the substance
= m/M
= 22g/44g
= 1/2 moles
= 0.5 moles
