Final answer:
The molar mass of oxalic acid dihydrate is calculated by adding the molar masses of carbon, hydrogen, and oxygen found in the chemical formula C2H2O4·2H2O. The total molar mass is 158.068 g/mol.
Step-by-step explanation:
To calculate the molar mass of oxalic acid dihydrate (also known as ethanedioic acid dihydrate), we need to consider the atomic masses of all the atoms in the formula and then add them up. Oxalic acid dihydrate has the chemical formula C2H2O4·2H2O. Here's how the calculation is done step-by-step:
Carbon (C): The molar mass of carbon is approximately 12.01 g/mol and there are two carbon atoms in oxalic acid, so 2 x 12.01 g/mol = 24.02 g/mol.
Hydrogen (H): The molar mass of hydrogen is approximately 1.008 g/mol. There are two hydrogen atoms in oxalic acid and an additional four hydrogen atoms in the dihydrate portion, so (2 + 4) x 1.008 g/mol = 6.048 g/mol.
Oxygen (O): The molar mass of oxygen is approximately 16.00 g/mol. There are four oxygen atoms in oxalic acid and another four in the dihydrate portion, so 8 x 16.00 g/mol = 128.00 g/mol.
Adding these together: 24.02 g/mol (carbon) + 6.048 g/mol (hydrogen) + 128.00 g/mol (oxygen) gives us the molar mass of oxalic acid dihydrate, which is 158.068 g/mol.