25 mL of a solution of barium hydroxide on titration with a 0.1 molar solution of hydrochloric acid gave a titre value of 35 mL. The molarity of barium hydroxide solution was :

Options

A. 0.28
B. 0.35
C. 0.07
D. 0.1

Answer

C

Explanation

`underset("1 mol")(Ba(OH)_(2))+underset("2 mol")(2HCl)rarrBaCl_(2)+2H_(2)O`
No. of moles of `HCl=(("0.1 mol"^(-1)))/(("1L"))xx("0.035L")`
`=3.5xx10^(-3)` mol
No. of moles of `Ba(OH)_(2)=(3.5xx10^(-3))/(2)`
`=1.75xx10^(-3)` mol
Molarity of `Ba(OH)_(2)` solution
`= ("No. of moles of Ba"("OH")_(2))/("Volume of solution in litres")`
`=((1.75xx10^(-3)"mol"))/(("0.025 L"))=0.07"mol L"^(-1)`
`=0.07M`.