20 ~mL of 0.1 M HCl is added to the 30 ~mL of 0.1 M NaOH . To this solution extra 50 ~mL of water was added. What is the molarity of the final solution formed?

Step-by-step solution

n _ HCl =0.1 M 0.02 ~L =0.002 ~mol n _ NaOH =0.1 M 0.03 ~L =0.003 ~mol Number of moles of NaOH remaining after neutralization. =0.003-0.002=0.001 ~mol . Total final volume =50 ~mL +50 ~mL =100 ~mL =0.1 ~L Molarity = 0.001 0.1 =0.01 M