Question

Calculate the final concentration of calcium nitrate when a solution is made by dissolving 25.0 mL of a 0.50 M solution of Ca(NO3)2 to a total volume of 125.0 mL.

Answer 1

Answer. Given data initial volume of solution V1=25 ml, molarity M=0.50 M

and final volume V2 = 125 ml

plan :first calculate number of moles of calcium nitrate then find concentration of calcium nitrate in the 125 ml solution using number of moles in first solution.

number of moles n=(Molarity x volume in ml)/1000

                           n =( 0.50 x 25)/1000=12.5/1000=0.0125 moles

molarity M= n x 1000/volume in ml

           M= 0.0125x 1000/125 = 0.10M.

The final concentration of calcium nitrate is 0.10 M