The product of uncertainty in velocity and uncertainty in position of a micro particle of mass 'm' is not less than in which of the following?

• h × $\frac{3\mathrm{\pi }}{\mathrm{m}}$

• $\frac{\mathrm{h}}{3\mathrm{\pi }}$× m

• $\frac{\mathrm{h}}{4\mathrm{\pi }} \times \frac{1}{\mathrm{m}}$

• $\frac{\mathrm{h}}{4\mathrm{\pi }} \times \mathrm{m}$

An element has [Ar] 3d¹ configuration in its +2 oxidation state. Its position in the periodic table is

• period - 3, group - 3

• penod - 3, group - 7

• period - 4, group - 3

• period - 3, group - 9

In which of the following molecules, all bond lengths are not equal?

• SF₆

• PCl₅

• BCl₃

• CCl₄

In which of the following molecules, maximum number of lone pairs is present on the central atom?

• NH₃

• H₂O

• ClF₃

• XeF₂

Which one of the following is the kinetic energy of a gaseous mixture containing 3g of hydrogen and 80g of oxygen at temperature T (K)?

• 3 RT

• 6 RT

• 4 RT

• 8 RT

A, B, C and D are four different gases with critical temperatures 304.1, 154.3, 405.5 and 126.0 K respectively. While cooling the gas, which gets liquefied first?

• B

• A

• D

• C

40 mL of x M KMnO₄ solution is required to react completely with 200 mL of 0.02 M oxalic acid solution in acidic medium. The value of x is

• 0.04

• 0.01

• 0.03

• 0.02

Given that,

C (s) + O₂ (g) → CO₂ (g) ; $∆\mathrm{H}°$ = -x kJ mol^-1

2CO (g) + O₂ (g) → 2CO₂ (g) ; $∆\mathrm{H}°$ = -y kJ mol^-1

The enthalpy of formation of CO will be

• $\frac{\mathrm{y} - 2\mathrm{x}}{3}$

• $\frac{\mathrm{y} - 2\mathrm{x}}{2}$

• $\frac{2\mathrm{x} - \mathrm{y}}{2}$

• $\frac{\mathrm{x} - \mathrm{y}}{2}$

At 400 K, in a 1.0 L vessel, N₂O is allowed to attain equilibrium, N₂O₄ (g) $\rightleftharpoons$ 2NO₂ (g)

At equilibrium, the total pressure is 600 mm Hg, when 20% of N₂O₄ is dissociated. The value of K_P for the reaction is

• 50

• 100

• 150

• 200

In which of the following salts, only cationic hydrolysis is involved?

• CH₃COONH₄

• CH₃COONa

• NH₄Cl

• Na₂SO₄