Question

question
identify the formula for chromic acid.
answer
$hcro_4$
$h_2cro_4$
$h_2cr_2o_7$
$h_2cro_3$
i dont know yet

Explanation:

Chromic acid corresponds to the chromate ion ($\text{CrO}_4^{2-}$). To form a neutral acid, two hydrogen ions ($\text{H}^+$) are needed to balance the 2- charge of the chromate ion.

Answer:

$\boldsymbol{\text{H}_2\text{CrO}_4}$ (the second option)