The chemical formula for rubidium chromate is Rb2CrO4.
The molar mass of Rb2Cr2O7 (rubidium dichromate) can be calculated by adding the atomic masses of all its constituent elements: 2 atoms of rubidium (Rb), 2 atoms of chromium (Cr), and 7 atoms of oxygen (O). The molar mass comes out to be approximately 387.87 g/mol.