$NaCl + K_2Cr_2O_7 + \text{conc. } H_2SO_4$ $\xrightarrow{\Delta} P(\text{gas})$ $\xrightarrow{NaOH} Q$ $\xrightarrow[Pb(CH_3COO)_2]{CH_3COOH} R(\text{ppt})$
Which of the following is the correct statement?

Provide the structures for:
$1.$ $MnO_4^{-}$
$2.$ $MnO_4^{2-}$

Determine the correct $(T)$ and incorrect $(F)$ statements from the following:
$(a)$ The $E^o$ for $MnO_4^- + 8H^+ + 5e^- \to Mn^{2+} + 4H_2O$ is $-1.52 \ V$.
$(b)$ $MnO_4^-$ oxidizes $I^-$ to $I_2$.
$(c)$ The color of $CrO_4^{2-}$ is yellow in the presence of $H^+$.
$(d)$ The color of $CrO_4^{2-}$ is yellow in the presence of $OH^-$.

Corundum is

When copper turnings and concentrated $HCl$ are heated with copper sulphate,the compound formed is:

When dilute $H_2SO_4$ is added to an aqueous solution of potassium chromate,the yellow color of the solution turns to orange. What does this indicate?