diketahui ar H=1 Ar C=12 Ar N=14 Ar O=16. Tentuian Mr (NH4)2 CO3

Mr = (Ar N × 2) + (Ar H × 8) + (Ar C × 1) + (Ar O × 3)
= (14 × 2) + (1 × 8) + (12 × 1) + (16 × 3)
= 28 + 8 + 12 + 48
= 96