Question

A 1.00 L volume of HCl reacted completely with 2.00 L of 1.50 M Ca(OH)2 according to the balanced chemical equation below. 2HCl + Ca(OH)2 mc013-1.jpg CaCl2 + 2H2O What was the molarity of the HCl solution? 0.375 M 1.50 M 3.00 M 6.00 M

Answer 1

The answer is D
6.00 M. I just took the test 

Answer 2

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