Question

if 80 g of X combines with 1.5x10^23 atoms of Y to form X Y2 without any of either element remaining, determine gram atomic weight of X

Answer 1

Answer provided by www.AssignmentExpert.com

#67967 Chemistry, Other

If $80\,\mathrm{g}$ of X combines with $1.5 \times 10^{23}$ atoms of Y to form $\mathrm{XY}_2$ without any of either element remaining, determine gram atomic weight of X.

Answer:

1 mole contains $6.04 \cdot 10^{23}$ atoms

According to the formula, the amount of X atoms in 2 times less than Y. Therefore:

$$X = 1.5 \times 10^{23} / 2 = 0.75 \times 10^{23}.$$

That is why, number of moles of X is: n (X) = 0.75 × 10²³ / 6.04 × 10²³ = 0.12 mol

$$n = m / M \quad M = m / n \quad M (X) = 80 / 0.12 = 645.2\,\mathrm{g/mol}$$