d- and f-Block Elements

Which of the following is not formed when $\ce{H2S}$ reacts with acidic $\ce{K2Cr2O7}$ solution ?

Which one of the following exhibits the largest number of oxidation states ?

Copper becomes green when exposed to moist air for a long period. This is due to :

The coloured solution S contains

Oxidation states of the metal in the minerals haematite and magnetite, respectively, are

Reduction of the metal centre in aqueous permanganate ion involves

The equilibrium
$$\ce{2Cu^{I} <=> Cu^{0} + Cu^{II}}$$
in aqueous medium at 25 °C shifts towards the left in the presence of

All the compounds listed in Column I react with water. Match the result of the respective reactions with the appropriate options listed in Column II.

The oxidation number of Mn in the product of alkaline oxidative fusion of $\ce{MnO2}$ is

The number of water molecule(s) directly bonded to the metal centre in $\ce{CuSO4*5H2O}$ is

Among the following, the coloured compound is

Consider a titration of potassium dichromate solution with acidified Mohr's salt solution using diphenylamine as indicator. The number of moles of Mohr's salt required per mole of dichromate is

While $\ce{Fe^{3+}}$ is stable, $\ce{Mn^{3+}}$ is not stable in acid solution because

Match the reactions in Column I with nature of the reactions/type of the products in Column II. Indicate your answer by darkening the appropriate bubbles of the 4 × 4 matrix given in the ORS.