ques 23 KM The flask shown here contains 100 mL of HCl and a

ques 23 K-M

The flask shown here contains 10.0 mL of HCl and a few drops of phenolphthalein indicator. The buret contains 0.260 M NaOH.

What volume of NaOH is needed to reach the end point of the titration?

What was the initial concentration of HCl?

Solution

Your question contains 2 unknowns -1) the concentration of the HCl , and the volume of NaOH solution used. It is impossible to calculate both unknowns. You must provide the data for 1 of these. Then the second unknown can be calculated.

M1 x V1 = M2 x V2
M1 x 10.0 = 0.260 x V2
V2 (volume of NaOH) = M1 x 10.0 / 0.260
M1 (initial concentration of HCl) = 0.260 x V2 / 10.0

you can calculate the unknows from the above equations BUT you need to know one unknown to solve for the second.