Question

Find molecular masses of K₂Cr₂O₇ and Cr₂(SO₄)₃.

Answer 1

here is your answer

▪molecular mass of K2Cr2O7 = 2×atomic mass of potassium + 2×atomic mass of chromium + 7×atomic mass of oxygen

molecular mass of K2Cr2O7 = (2×38)+(2×52)+(7×16)
= 76+104+112
= 292

▪ molecular mass of Cr2(SO4)3 = 2×atomic mass of chromium + 3×atomic mass of sulphur + 12×atomic mass of oxygen

molecular mass of Cr2(SO4)3
= (2×52)+(3×32)+(12×16)
= 104+96+192
= 392