Question

What is the molar mass of H2CO3? (Molar mass of H = 1.0079 g/mol; C = 12.010 g/mol; O = 15.999 g/mol)

Answer 1

You have to multiply the molar mass of each element by the number of atoms there are in the compound and then add each element's molar mass in the compound.
There are 2 Hydrogen atoms, one carbon atom and 3 oxygen atoms

H = 2(1.0079 g/mol) = 2.0158 g/mol
C = 12.010 g/mol
O = 3(15.999g/mol)= 47.997 g/mol


H2CO3 = (2.0158+12.010+47.997) g/mol= 62.02

The molar mass of H2CO3 is C. 62.02 g/mol

Answer 2

The molar mass is 62.03 g/mol