Question

Sulphur burns in air to form sulphur dioxide: `S + O_2 -> SO_2`. What is the mass of sulphur that must be burned to produce 64g of sulphur dioxide?

Answer 1

About `32*g`.

Explanation:

This problem uses your understanding of equivalent mass. The combustion of sulfur may be represented by the following equation:

`underbrace(S(s) + O_2(g) rarr SO_2(g))_"64 g of reactant gives 64 g of product"`

And given molar masses, the reaction EXPLICITLY states that `32*g` of sulfur is oxidized by `32*g` to give `64*g` of sulfur dioxide - these are all the equivalent masses of the reactants and products, which contain stoichiometric quantities of reactant and product.