The self ionisation constant for pure formic acid, K=[HCOO ][ HCOO- ] has been estimated as 10-6 at room temperature. The density of formic acid is 1.15 g / cm 3. The percentage of formic acid molecules in pure formic acid are converted to formate ion:

Question

The self ionisation constant for pure formic acid, K=[HCOO ][ HCOO- ] has been estimated as 10-6 at room temperature. The density of formic acid is 1.15 g / cm 3. The percentage of formic acid molecules in pure formic acid are converted to formate ion: (A) 0.002 % (B) 0.004 % (C) 0.006 % (D) 0.008 %

Tardigrade Admin · Accepted Answer

Given density of formic acid =1.15 g / cm 3 ∴ Weight of formic acid in 1 litre solution =1.15 × 103 g Thus, [ HCOOH ]=(1.15 × 103/46)=25 M Since in case of auto-ionisation [ HCOOH 2+]=[ HCOO- ] and [ HCOO- ][ HCOOH 2+]=10-6 ⇒ [ HCOO -]=10-3 Now % dissociation of HCOOH =([ HCOO -] × 100/[ HCOOH ])=(10-3/25) × 100 =0.004 %

Q. The self ionisation constant for pure formic acid, $K = [H COO] [H CO O^{-}]$ has been estimated as $1 0^{- 6}$ at room temperature. The density of formic acid is $1.15 g / c m^{3}$ . The percentage of formic acid molecules in pure formic acid are converted to formate ion:

$0.002%$

$0.004%$

$0.006%$

$0.008%$

Q. The self ionisation constant for pure formic acid, K=[HCOO][HCOO−] has been estimated as 10−6 at room temperature. The density of formic acid is 1.15g/cm3. The percentage of formic acid molecules in pure formic acid are converted to formate ion:

0.002%

0.004%

0.006%

0.008%

Q. The self ionisation constant for pure formic acid, $K = [H COO] [H CO O^{-}]$ has been estimated as $1 0^{- 6}$ at room temperature. The density of formic acid is $1.15 g / c m^{3}$ . The percentage of formic acid molecules in pure formic acid are converted to formate ion:

$0.002%$

$0.004%$

$0.006%$

$0.008%$