How many of the following salts are white and soluble in dilute ${\mathrm{HNO}}_3$?
${\mathrm{BaCrO}}_4,{\mathrm{Hg}}_2{\mathrm{CrO}}_4,\mathrm{ZnS},{\mathrm{BaSO}}_4,{\mathrm{CH}}_3\mathrm{COOAg},{\mathrm{AgNO}}_2$

BaCrO₄ - Yellow, soluble in dil HNO₃
Hg₂CrO₄- Red, soluble in conc.HNO₃
ZnS- White, soluble in conc.HNO₃
BsSO₄- White, insoluble in all mineral acids
CH₃COOAg and AgNO₂ all are white solid
and are soluble in dilute HNO₃ solution