Question

Calculate the volume strength of `H_2O_2` solution if 50 " mL of " this diluted solution required 40 " mL of " `(M)/(60)` `K_2Cr_2O_7` solution in presence of `H_2SO_4` for complete reaction.

Answer 1

`H_2O_2-=Cr_2O_7^(2)`
`(n=2)(n=6)`
`mEq-=mEq`
`N_1V_1-=N_2V_2`
`N_1xx20-=(1)/(60)xx6xx40`
`N(H_2O_2)=(4)/(20)=0.2N`
The normality of the 50 " mL of " `H_2O_2` should be twice the normality of 20 " mL of " the diluted solution of `H_2O_2`. Since the volume of `H_2O_2` solution has doubled.
`(50 " mL of " H_2O_2+50" mL of " H_2O=` 100 " mL of " solution of `H_2O_2`)
`N(H_2O_2) of 50 " mL of " H_2O_2=0.2xx2=0.4N`
Volume strength of `H_2O_2=5.6xx0.4=2.24` volume of `O_2`