Molecular Empirical Formula

Urea is an organic compound with the molecular formula . It consists of two amine groups ( ) attached to a carbonyl group ( ). The correct molecular formula for urea is , making D the correct answer.

The metal in the nitrate has a valency of 2, as indicated by the formula . For the phosphate, the phosphate ion has a valency of 3. To balance the charges, we need three ions for every two ions. Therefore, the formula of the phosphate will be .