$K_2Cr_2O_7 \xrightarrow{\Delta} A + B + C$
If $B$ is a green-colored compound,then it would be:

Which alloy is used for making coins?

Which of the following is incorrect about $K_{2}Cr_{2}O_{7}$?

Assertion: $KMnO_4$ is purple in colour due to charge transfer.
Reason: There is no electron present in $d$-orbitals of Manganese in $MnO_4^-$.

Correct statement for $CeO_2$ is/are:
$1$. It is diamagnetic in nature.
$2$. It is a good oxidising agent.
$3$. It is a colourless compound.

An acidified solution of potassium chromate was layered with an equal volume of amyl alcohol. When it was shaken after the addition of $1 \ mL$ of $3 \% \ H_2O_2$,a blue alcohol layer was obtained. The blue color is due to the formation of a chromium$(VI)$ compound '$X$'. What is the number of oxygen atoms bonded to chromium through only single bonds in a molecule of $X$ ?