Question

The titration of 20.0 mL of an unknown concentration `H_2SO_4` solution requires 83.6 mL of 0.12 M `LiOH` solution. What is the concentration of the `H_2SO_4` solution (in M)?

Answer 1

`(C_M)_(H_2SO_4) = 0.25 \ mol.L^-1`

Explanation:

Write a balanced chemical equation for the neutralization reaction to figure out the mole relationship between the sulfuric acid and lithium hydroxide.

`H_2SO_4 + 2LiOH -> Li_2SO_4 + 2H_2O`

`n_(H_2SO_4) = 1/2 \ n_(LiOH)`

`underbrace((C_MxxV))_("number of moles of "H_2SO_4) = 1/2\ \ \ \ \ \ xxunderbrace((C_MxxV))_("number of moles of "LiOH)`

Note that `C_M` is the molar concentration and `V`is the volume of solution.

`(C_MxxV)_(H_2SO_4) = 1/2( C_MxxV)_(LiOH)`

`(C_M)_(H_2SO_4) = (C_MxxV)_(LiOH)/( 2* V_(H_2SO_4)`

`(C_M)_(H_2SO_4) = (0.12 \ mol.L^-1xx 83.6 \ mL)/( 2xx20.0 \ mL)`

`(C_M)_(H_2SO_4) = (0.12 \ mol.L^-1xx 83.6 \ cancel (mL))/( 2xx20.0 \ cancel(mL))`

`(C_M)_(H_2SO_4) = 0.25 \ mol.L^-1`