What happerns when:
a. Chromium hydrogen is treated with hydrogen peroxide in the presence of sodium hydroxide.
b. Hydrogen peroxide is added to ferrous ammonium sulphate solution.
c. hydrogen peroxide is added to acidified potassium permanganate.
d. An alkaline solution of potassium ferricyanide is reacted with `H_(2)O_(2)`.

Explanation

a. Chromium hydroxide is converted into soluble yellow sodium chromate.
`{:(" "[H_(2)O_(2)toH_(2)O+[O]]xx3),(Cr+(OH)_(3)+4NaOH+3[O]to2Na_(2)CrO_(4)+5H_(2)O),(ulbar(2Cr(OH)_(3)+4NaOH+3H_(2)O_(2)to2Na_(2)CrO_(4)+8H_(2)O)):}`
b. Ferrous ammonim sulphate is oxidised to ferric salt.
`{:(" "[H_(2)O_(2)toH_(2)O+[O]]),([O]+2FeSO_(4)+H_(2)SO_(4)toFe_(2)(SO_(4))_(3)+H_(2)O),(ulbar(2FeSO_(4)+3H_(2)SO_(4)+H_(2)O_(2)toFe_(2)(SO_(4))_(3)+2H_(2)O)):}`
c. Potassium permangnete is decolourised. `{:(2KMnO_(4)+H_(2)SO_(4)toK_(2)SO_(4)+2MnSO_(4)+3H_(2)O+5[O]),(" "[H_(2)O_(2)+[O]toH_(2)O+O_(2)]xx5),(bar(2KMnO_(4)+3H_(2)SO_(4)+5H_(2)O_(2)toK_(2)SO_(4)+2MnSO_(4)+8H_(2)O+5H_(2)O)):}`
d. Potassium ferricyanide is reduced to potassium ferrocyanide.
`{:(2K_(3)[Fe(CN)_(6)]+2KOHto2K_(4)[Fe(CN)_(6)]+H_(2)O),(" "H_(2)O_(2)+[O]toH_(2)O+O_(2)),(ulbar(2K_(3)[Fe(CN)_(6)]+2KOH+H_(2)O_(2)to2K_(4)[Fe(CN)_(6)]+2H_(2)O+O_(2))):}`