Question

How many moles of HCl are required to completely neutralize 0.30 moles of Ca(OH)2?
0.30 moles
0.60 moles
0.15 moles
1.0 moles

Answer 1

First have a look at the balanced chemical reaction:

\[2HCl+Ca(OH)_2 \rightarrow 2H_2O+CaCl_2\]
You can see from this reaction that for every mole of Ca(OH)2 that react, TWICE as many moles of HCl also react. So for your question, if you have 0.30 mol of Ca(OH)2, how many moles of HCl must have reacted with it?