To find the molar mass of water (H2O), we first need to find the molar mass of hydrogen (H) and oxygen (O) separately.

The molar mass of hydrogen (H) is 1 g/mol and there are 2 atoms of hydrogen in water (H2O), so the total molar mass of hydrogen in water is:
1 g/mol * 2 = 2 g/mol

The molar mass of oxygen (O) is 16 g/mol.

Adding the molar masses of hydrogen and oxygen gives us the molar mass of water:
2 g/mol (H) + 16 g/mol (O) = 18 g/mol

Therefore, the molar mass of water (H2O) is 18 g/mol.