3) a)Calculate the molar mass of Na2o b)Find the molecular mass of 10 CO2

a) Molar mass of Na2O is the sum of the atomic masses of two sodium atoms and one oxygen atom. The atomic mass of sodium is 23 and that of oxygen is 16.

(2*23)+16= 46+16=62. Hence, the molar mass of Na2O is 62.

b) Molecular mass of 10 CO2 = 10* Molar mass of CO2

Molar mass of CO2 is the sum of atomic masses of one carbon atom and two oxygen atoms.

12.01+(2*16)=12.01+32=44.01. Hence, the molar mass of CO2 is 44.01.

The mass of 10 molecules of CO2 is 10*44.01=440.1