# In a mixture having nitrite and nitrate can be destroyed by heating with

(a) $Na_2CO_3$
(b) Urea
(c) Oxalic acid
(d) NaCl

$NaNO_2 + H_2SO_4 \longrightarrow Na_2SO_4 + 2HNO_2$
$2HNO_2 + NH_2CONH_2 \xrightarrow{\Delta} 3H_2O + CO_2 \uparrow + 2N_2$
Thus, Sodium nitrite can be destroyed by introducing $H_2SO_4$ to the mixture and then heating it with Urea.
answered Feb 1, 2014