To find the molar mass of CaO from Ca(OH)2, we first need to calculate the molar mass of Ca(OH)2 and then find the molar mass of CaO.

Molar mass of Ca(OH)2:
Calcium (Ca) has a molar mass of 40.08 g/mol.
Oxygen (O) has a molar mass of 16.00 g/mol.
Hydrogen (H) has a molar mass of 1.01 g/mol.

Ca(OH)2 is composed of one calcium atom, two hydrogen atoms, and two oxygen atoms:
Mass of Ca = 1 x 40.08 = 40.08 g/mol
Mass of O = 2 x 16.00 = 32.00 g/mol
Mass of H = 2 x 1.01 = 2.02 g/mol

Molar mass of Ca(OH)2 = 40.08 + 32.00 + 2.02 = 74.10 g/mol

Now, to find the molar mass of CaO, we need to subtract water (H2O) from Ca(OH)2:
Molar mass of H2O = 2(1.01) + 16.00 = 18.02 g/mol
Molar mass of CaO = Molar mass of Ca(OH)2 - Molar mass of H2O
Molar mass of CaO = 74.10 g/mol - 18.02 g/mol
Molar mass of CaO = 56.08 g/mol

Therefore, the molar mass of CaO is 56.08 g/mol.