The following reaction is used to produce tungsten(VI)oxide: WS3(s) + O2(g) �¨ WO3(s) + SO2(g)

Question

The WO3 is then heated and undergoes a decomposition reaction produce tungsten and oxygen gas. How many grams of tungsten could be produced if 39.27 grams of WS3 are used

Answer 1

You should first balance the equation given.

WS3(s) + O2(g) -> WO3(s) + SO2(g)

But you should see that one mole of WS3 must yield one mole of WO3.

You also have the decomposition of WO3

WO3 -> W + O2

Again one mole of WO3 yields one mole of W metal.

So calculate the number of moles of WS3 you are starting with from
39.27/(molar mass of WS3)

this is the same number of moles of W metal produced so mass produced

39.27x(molar mass of W)/(molar mass of WS3)