# Reaction with Limiter

1. Oct 18, 2008

### MellowOne

1. The problem statement, all variables and given/known data
A sample of 5.53g of Mg(OH)2 is added to 25.0mL of 0.200M HNO3. How many moles of Mg(OH)2, HNO3, and Mg(NO3)2 are present after the reaction is complete?

2. Relevant equations
M = mol/L

3. The attempt at a solution
The balanced equation for the reaction is Mg(OH)2 + 2HNO3 -> Mg(NO3)2 + 2H2O

The limiter in this case would be HNO3 and I found that in 0.025L of this solution there is 0.315g of HNO3.

What I'm not sure is how to find the moles of each after the reaction is complete. I assume it's with stoichiometry, but I'm not sure how to find the moles of each at the end. I know that there should be 0 moles of HNO3 because it's used up correct? As for the Mg(OH)2, am I suppose to subtract the grams of HNO3 from the 5.53g of Mg(OH)2?

2. Oct 20, 2008

### Staff: Mentor

That's right.

Convert Mg(OH)2 to moles.

Look at the coefficients in the reaction equation.

How many moles of Mg(OH)2 will react with HNO3?

How many moles of MgCl2 will be produced?

How many moles of Mg(OH)2 will be left?