Question -
Answer -
(i) H2O:
The molecular mass of water, H2O
= (2 ×Atomic mass of hydrogen) + (1 × Atomic mass of oxygen)
=[2(1.0084) + 1(16.00 u)]
= 2.016 u +16.00 u
= 18.016
= 18.02 u
(ii) CO2:
The molecular mass of carbon dioxide, CO2
= (1 ×Atomic mass of carbon) + (2 × Atomic mass of oxygen)
= [1(12.011u) + 2 (16.00 u)]
= 12.011 u+ 32.00 u
= 44.01 u
(iii) CH4:
The molecular mass of methane, CH4
= (1 ×Atomic mass of carbon) + (4 × Atomic mass of hydrogen)
= [1(12.011u) + 4 (1.008 u)]
= 12.011 u+ 4.032 u
= 16.043 u