X4O10Let molar mass of X be ymolar mass = 4y + 10 x 16 = 4y+160 so, moles = 85.2 / (4y+160) Moles of oxygen = 10 x [85.2 / (4y+160) ]Mass of oxygen = 16 x 10 x [85.2 / (4y+160) ]which is 48.0 so, 48 = 16 x 10 x [85.2 / (4y+160) ] Solve the equation to get y. y = 31
