Ncert Solutions Chemistry Class 12th

The chemical that is added to reduce the melting point of the reaction mixture during the extraction of aluminium is:

Compound with molecular formula C?H?O can show:

Reagent, 1-naphthylamine and sulphanilic acid in acetic acid is used for the detection of :

KBr is doped with 10⁻⁵ mole percent of SrBr₂. The number of cationic vacancies in 1 g of KBr crystal is ______ 10¹⁴. (Round off to the nearest integer).
[Atomic Mass: K: 39.1 u, Br: 79.9 u, NA = 6.023 *10²³]

A 1 molal K4[Fe(CN)6] solution has a degree of dissociation of 0.4. Its boiling point is equal to that of another solution which contains 18.1 weight percent of a non electrolytic solute A. The molar mass of A is ______ u. (Round off to the nearest integer).
[Density of water = 1.0 g cm?³]

Consider the above reaction. The percentage yield of amide product is ______.
Benzoyl chloride (0.140 g) + Diphenylamine (0.388 g) → N,N-Diphenylbenzamide (0.210 g)
(Round off to the nearest integer).
(Given: Atomic mass: C: 12.0 u, H:1.0 u, N: 14.0 u, O: 16.0 u, Cl: 35.5 u)

The standard enthalpies of formation of Al₂O₃ and CaO are –1675 kJ mol⁻¹ and -635 kJ mol⁻¹ respectively.
For the reaction 3CaO + 2Al → 3Ca + Al₂O₃ the standard reaction enthalpy ΔᵣH° = _______ kJ.
(Round off to the nearest integer).

15 mL of aqueous solution of Fe²⁺ in acidic medium completely reacted with 20 ml of 0.03 M aqueous Cr₂O₇^2-. The molarity of the Fe²⁺ solution is _______ *10^-2 M (Round off to the nearest integer).

The reaction of white phosphorous on boiling with alkali in inert atmosphere resulted in the formation of product 'A'. The reaction of 1 mol of 'A' with excess of AgNO₃ in aqueous medium gives _______ mol(s) of Ag. (Round off to the nearest integer).