Question

If 29.4 grams of hydrogen and 3701.3 grams of iodine combine to form hydrogen iodide, how many grams of hydrogen iodide must form?

Answer 1

`3.730kg`

Explanation:

First write down a balanced chemical equation for the reaction :

`H_2+I_2->2HI`

This represents the mole ratio in which chemicals combine.

Now calculate the number of moles of each reactant present :

`n_(H_2)=m/M_r=29.4/2=14.7mol`

`n_(I_2)=m/M_r=3701.3/253.8=14.583mol`

Since the balanced chemical equation illustrates that the reactants combine in a `1:1` ratio, it implies that iodine is the limiting reagent and decides how much product is formed. Hydrogen is in excess.

So hence, since `1mol I_2` produces `2molHI`, it follows that `14.583molI_2` will produce `29.166molHI`

This corresponds to a mass of product of

`m=nxxM_r`

`=29.166xx127.9`

`=3730.33g`