Answer: The Molar mass of Cro2 (or Chromium (IV) oxide) is 83.9949 g/mol.
Explanation: The atomic mass of Chromium is 51.9961 and the atomic mass of Oxygen is 15.9994. You then add both numbers and multiply by 2. Put it in the calculator like this: 51.9961 + 15.9994 x 2 and you will get 83.9949 g/mol.