Mᵣ(K₂CO₃) = 2Aᵣ(K) + Aᵣ(C) + 3Aᵣ(O) = 2*39 + 12 + 3*16 = 78 + 12 + 48 = 138 а.е.м.
Mᵣ(MgSO₄) = Aᵣ(Mg) + Aᵣ(S) + 4Aᵣ(O) = 24 + 32 + 4*16 = 24 + 32 + 64 = 120 а.е.м.
Mᵣ(K₂CO₃) = 2Aᵣ(K) + Aᵣ(C) + 3Aᵣ(O) = 2*39 + 12 + 3*16 = 78 + 12 + 48 = 138 а.е.м.
Mᵣ(MgSO₄) = Aᵣ(Mg) + Aᵣ(S) + 4Aᵣ(O) = 24 + 32 + 4*16 = 24 + 32 + 64 = 120 а.е.м.