# Calculating amount of HCL required

1. Aug 16, 2016

### JonnyG

1. The problem statement, all variables and given/known data
Suppose Iron(II) Sulfide is reacted with hydrogen chloride. How many grams of HCl is required is react with 75.0 grams of Iron (II) Sulfide ore of which 30% is inactive.

2. Relevant equations

3. The attempt at a solution

EDIT: Nevermind I solved it. Obviously 43.6 g of $2 \mathrm{HCl}$ is the same as 43.6 g of $\mathrm{HCl}$.

Only 70% of the Iron (II) Sulfide is active, so we can just pretend we are dealing with 52.5 g of Iron (II) Sulfide. Now, the equation is $\mathrm{FeS} + 2\mathrm{HCl} \rightarrow \mathrm{FeCl}_2 + \mathrm{H}_2 \mathrm{S}$.

1 mole of $\mathrm{FeS} = 87.95$ g and 1 mole of $2\mathrm{HCl} = 73$ g. Because 52.5/87.95 = 0.597 then we only need (0.597)(73) = 43.6 g of $2 \mathrm{HCl}$ for the reaction, which is equivalent to (43.6)(2) = 87.2 g of $\mathrm{HCl}$. Is this correct? A couple answers that I read online says that the answer is 43.6 g of $\mathrm{HCl}$ rather than 43.6 g of $2 \mathrm{HCl}$.

2. Aug 16, 2016

### BvU

Well, on a scale it comes down to exactly the same quantity of $HCl$