Question

What is the limiting reagent when 3.10 mol of `SO_2` reacts with 2.75 mol of `O_2` according to the equation: `SO_2 + O_2 -> SO_3`?

Answer 1

Your equation is incorrect; it is not stoichiometrically balanced.

Explanation:

Synthesis of sulfur trioxide is represented stoichiometrically:

`SO_2(g) + 1/2O_2(g) rarr SO_3(g)`

This equation tells us that `64*g` of sulfur dioxide reacts with `16` dioxygen gas to give `80*g` of sulfur trioxide.

Clearly, given this equation, there is excess dioxygen gas. The given molar quantity of sulfur dioxide requires only `1.6*mol` dioxygen gas.

You will have to calculate the mass of product yourself.