Am I doing this right? What mass of "HCl" reacts with "3.26 g" of "Mg"("OH")_2?
"3.26 g Mg"("OH")_2 xx ("1 mol Mg"("OH")_2)/("58.326 g Mg"("OH")_2) xx ("2 mol HCl")/("1 mol Mg"("OH")_2) xx "36.458 g HCl"/"1 mol HCl"
= "4.075 g"
1 Answer
Here's what I would do. Since
The balanced equation is
2"HCl"(aq) + "Mg"("OH")_2(s) -> 2"H"_2"O"(l) + "MgCl"_2(aq)
So we use the general pathway
"g Mg"("OH")_2 stackrel(-: "g/mol Mg"("OH")_2)(->) "mols Mg"("OH")_2 stackrel(xx "mol HCl"/("mol Mg"("OH")_2))(->) "mols HCl" stackrel(xx "g/mol HCl")(->) "g HCl"
to write out
3.26 cancel("g Mg"("OH")_2) xx cancel("1 mol Mg"("OH")_2)/(58.3188 cancel("g Mg"("OH")_2)) xx (2 cancel("mol HCl"))/cancel("1 mol Mg"("OH")_2) xx "36.4609 g HCl"/cancel"1 mol HCl"
= color(blue)("4.08 g HCl")
It looks like your mathematical process is right, but you seem to have used slightly different molar masses.
I used