Calculate the molar mass of a chemical compound by entering its chemical formula (e.g., H2O, NaCl, C6H12O6).
Note: Use standard capitalization (e.g., NaCl, not NAcl or nacl). Supports common pharmaceutical elements (H, C, N, O, Na, Mg, P, S, Cl, K, Ca, Fe, Zn, Br, I).