$K_2Cr_2O_7$ is preferred to $Na_2Cr_2O_7$ for use in volumetric analysis as a primary standard because

$Na_2Cr_2O_7$ is hygroscopic while $K_2Cr_2O_7$ is not

$K_2Cr_2O_7$ is hygroscopic while $Na_2Cr_2O_7$ is not

$K_2Cr_2O_7$ is pure while $Na_2Cr_2O_7$ is impure

What would happen when a solution of potassium chromate is treated with an excess of dilute $HNO_3?$

$Cr_2O_7^{2-}$and $H_2O$ are formed

$CrO_4^{2-}$is reduced to +3 state of Cr

$CrO_4^{2-}$is oxidised to +7 state of Cr

$Cr^{3+}$and $Cr_2O_7^{2-}$are formed

$Na_2Cr_2O_7$ is hygroscopic while $K_2Cr_2O_7$ is not

$Cr_2O_7^{2-}$and $H_2O$ are formed

Oxidation of oxalic acid by acidified $K M n O_{4}$ is an example of autocatalysis, it is due to the presence of

In the preparation of $K M n O_{4}$ , pyrolusite ( $M n O_{2}$ ) is first converted to potassium manganate ( $K_{2} M n O_{4}$ ). In this conversion, the oxidation state of manganese changes from

Deep green precipitate of $C r (O H)_{3}$ gives yellow solution on addition $H_{2} O_{2}$ in presence of excess of base. The yellow colour is due to

$K_{2} C r_{2} O_{7}$ is preferred to $N a_{2} C r_{2} O_{7}$ for use in volumetric analysis as a primary standard because

What would happen when a solution of potassium chromate is treated with an excess of dilute $H N O_{3} ?$

A student accidentally added conc. $H_{2} S O_{4}$ to potassium permanganate and it exploded due to the formation of an explosive which is