Determine the molar mass of each of the following compounds, all of which are used as fertilizers for the production of biomass.

(a) Calcium sulfate, CaSO₄, 

(b) Urea, CO(NH₂)₂, 

(c) Carnallite, H₁₂Cl₃KMgO₆.

Strategy We must determine the mass contributed by each element and then add them up to calculate the molar mass. When parentheses appear in the formula, each atom inside the parentheses must be multiplied by its own subscript and by the subscript appearing after the right-hand parenthesis.