How many mL of a 0.5M Ca(OH)2 solution are needed to neutralize 38mL of a 2M HNO3 solution?

Answer 1

2HNO3 + Ca(OH)2 ==> Ca(NO3)2 + 2H2O

mols HNO3 = M x L = ?
Convert mols HNO3 to mols Ca(OH)2 using the coefficients in the balanced equation.
The mols Ca(OH)2 = M x L. You know M and mols, solve for L and convert to mL.