Question

8.0g of mettalicoxide were reduced by hydrogen to give a metal of 2.0g. Calculate the mole of d metal that will combined with 0.5moles of oxygen.

Answer 1

This is done the same way as the last problem with Cu and Ag.
step 1. Write and balance the equation.
step 2. convert grams to mols.
step 3. convert mols of what you have to mols of what you want.
step 4. Not asked for in this problem but if needed, then grams = mols x molar mass.

Answer 2

2 grams of M in 8 grams of MOn
where M is metal symbol and n is O atoms per metal atom

There were 8-2 = 6 grams of O in MOn

6 grams of O * (1 mol of O/16 grams) = 6/16 = 3/8 mol of O which is 3/16 mol of O2

so 3/16 mol of O2 combines with 2 grams metal
so .5 mol of O2 combines with 16/3 or 5.33 grams of metal