Hydrofluoric acid is a weak acid. At 25°C, the molar conductivity of 0.002 M HF is 176.2 ${\mathrm{\Omega }}^{-1}$cm² mol^-1. If its $\wedge {°}_{\mathrm{m}}$ = 405.2 ${\mathrm{\Omega }}^{-1}$ cm² mol^-1. Equilibrium constant at the given concentration is

• 6.7 $\times$ 10^-4 M

• 3.2 $\times$ 10^-4 M

• 6.7 $\times$ 10^-5 M

• 3.2 $\times$ 10^-5 M

A buffer solution contains 500 mL of 0.2 M CH₃COONa and 500 ml of 0.1 M CH₃COOH .1 L of water is added to this buffer , pH before and after dilution will be (pka of CH₃COOH = 4.74)

• 3.74

• 5.04

• 5.90

• 7.70

Assertion : Heat of neutralisation of nitric acid with NaOH is same to that of HCI and NaOH.

Reason : In both cases strong acid and strong bases are neutralised.

H⁺ + OH^- $\to$H₂O

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

The conjugate base of (CH₃)₂NH₂⁺ is :

• (CH₃)₃N

• (CH₃)₂NH

• (CH₃)₂N^-

• (CH₃)₂N⁺

Assertion : Ice $\rightleftharpoons$ water, if pressure is applied water will evaporate.

Reason : Increases of pressure pushes the equilibrium towards the side in which number of gaseous molecule increases.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion : In an acid-base titration involving strong base and a weak acid, methyl orange can be used as an indicator.

Reason : Methyl orange changes its colour in pH range of 7 to 9.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

The K_sp of Mg(OH)₂ is 1 x 10^-12 , 0.01 M Mg(OH)₂ will precipitate at the limited pH :

• 3

• 9

• 5

• 8

NH₄COONH₂ (s) $\rightleftharpoons$ 2NH₃ (g) + CO₂ (g) ,if equlibrium pressure is 3 atm for the above reaction .K_p for the reaction is :

• 4

• 27

• 4/27

• 1/27

The pH of the solution obtained on neutralisation of 40 mL 0.1 M NaOH with 40 mL 0.1 M CH₃COOH is

• 7

• 8

• 6

• 3

In P versus V graph, the horizontal line is found in which exists

• Gas

• Liquid

• Equilibrium between gas and liquid

• Super critical temperature