The mass of `K_(2)Cr_(2)O_(7)` required to produce 5.0 L `CO_(2)` at `77^(@)C` and 0.82 atm pressure from excess of oxalic acid and volume of 0.1 N `NaOH` required to neutralise the `CO_(2)` evolved respectively are

Options

A. `7g, 2.86L`
B. `5g, 1.86L`
C. `4g,0.86L`
D. `14g,2.86L`

Answer

D

Explanation

`H_(2)C_(2)O_(4) rarr 2CO_(2) +2H^(+) +2e^(-)`
Moles of `CO_(2) =(PV)/(RT) = (0.82 xx 5)/(0.082 xx 350) = (1)/(7)`
`rArr (1)/(7) (W_(K_(2)Cr_(2)O_(7)))/(49) rArr W_(K_(2)Cr_(2)O_(7)) = 7g` and `(1)/(7)mol CO_(2) -= (1)/(7) mol H_(2)CO_(3) = (2)/(7)` Eqts
`(2)/(7) = 0.1 xx V = 2.86L`
Volume of `NaOH,V = 2.86` lit