The molarity of the HCl solution is 6.00M
Calculation
2HCl + Ca(OH)2→ CaCl2 +2H2O
Step 1:find the moles of Ca(OH)2
= molarity x volume
= 2l x 1.5 mol/l = 3 .00 moles
Step 2:use the mole ratio of HCl : Ca(OH)2 to calculate the moles of HCl
That is Ca(OH)2 :HCl is 2:1 therefore the moles of HCl= 3.00 moles x2= 6.00 moles.
step 3: find the molarity of HCl
molarity of HCl = moles of HCL / volume in liters of HCl
= 6.00 moles/ 1 L = 6.00 M