Question

what is the molar mass of (NH4)3 PO4? 113g, 121g, 149g, 339g

Answer 1

(NH4)3PO4 :

N = 14 * 3 =  42
H = 1 * 12 = 12
P = 31 * 1 = 31
O = 16 * 4 = 64
-------------------------
42+12+31+64 =  149 g / mol

Hope this helps!.