Chemistry NCERT Exemplar Solutions Class 12th Chapter Six

For the reaction

H₂F₂(g) ® H₂(g) + F₂(g)

$\Delta U=-59.6kJmo{l}^{-1}at27°C$

The enthalpy change for the above reaction is ()__________kJ mol^-1. [nearest integer]

The metal that is not extracted from its sulfide ore is

Among the following the number of state variable is____________.

Internal energy (U)

Volume (V)

Heat (q)

Enthalpy (H)

Dinitrogen and dioxygen, the main constituents of air do not react with each other in atmosphere to form oxides of nitrogen because

For one mole of an ideal gas, which of these statements must be true?

$\mathrm{U}$ and $\mathrm{H}$ each depends only on temperature

Compressibility factor $z$ is not equal to 1

${\mathrm{C}}_{\mathrm{P},\mathrm{m}}-{\mathrm{C}}_{\mathrm{v},\mathrm{m}}=\mathrm{R}$

$\mathrm{d}\mathrm{U}={\mathrm{C}}_{\mathrm{V}}\mathrm{d}\mathrm{T}$ for any process

Among statements (a) - (d), the correct ones are:

(a) Lime stone is decomposed to $\mathrm{C}\mathrm{a}\mathrm{O}$ during the extraction of iron from its oxides.

(b) In the extraction of silver, silver is extracted as an anionic complex.

(c) Nickel is purified by Mond's process.

(d) Zr and Ti are purified by Van Arkel method.

4.0 L of an ideal gas is allowed to expand isothermally into vacuum until the total volume is 20L. The amount of heat absorbed in this expansion is _________L atm.

Given are two statements one is labeled as Assertion A and other is labeled as Reason R.

Assertion A : Magnesium can reduce Al₂O₃ at a temperature below 1350°C, while above 1350°C aluminium can reduce MgO

Reason R : The melting and boiling points of magnesium are lower thatn those of aluminium.

In light of the above statements, choose most appropriate answer for the options given below