Question #0cbe1

1 Answer
Jan 14, 2018

The tequired mass of sulfur is 25g.

Explanation:

We have a very simple chemical reaction equation:

S+O2SO2

This the ratio of reactant to product is one mole of sulfur to one mole of sulfur dioxide. But next we have to find the total number of moles corresponding to 50g of sulfur dioxide.

To do that add p the atomic weights to get the molecular weight:

(32g Smol)+2×(16g Omol)=(64g SO2mol)

And then divide this into the given mass of sulfur dioxide:

50g SO2(64g SO2mol)=0.78mol SO2

Only two significant digits are used because, in fact, the given atomic weight of sulfur is correct only to that accuracy (four significant digits would be 32.06).

So we have 0.78 mole of sulfur dioxide meaning there must be 0.78 of sulfur. Then multiplying by the atomic weight gives the required mass of sulfur:

(0.78mol S)×32gmol=25g S