Equilibrium

Which of the following will decrease the pH of  a 50 mL solution of 0.01 M HCl?

• Addition of 5 mL of 1 M HCl

• Addition of 50 mL of 0.01 M HCl

• Addition of 50 mL of 0.002 M HCl

• Addition of Mg

Under which of the following conditions is the relation $∆\mathrm{H} =∆\mathrm{E} + \mathrm{P}∆\mathrm{V}$ valid for a closed system ?

• Constant pressure

• Constant temperature

• Constant temperature and pressure

• Constant temperature, pressure and composition

For a reversible chemical reaction where the forward process is exothermic, which of the following statements is correct ?

• The backward reaction has higher activation energy than the forward reaction.

• The backward and the forward processes have the same activation energy.

• The backward reaction has lower activation energy

• No activation energy is required at all since energy is liberated in the process.

0.1M HCl and 0.1M H₂SO₄ each of volume 2 mL are mixed and the volume is made upto 6 mL by adding 2 mL of 0.01N NaCl solution. The pH of the resulting mixture is

• 1.17

• 1.0

• 0.3

• log 2 - log 3

A weak acid of dissociation constant 10^-5 is being titrated with aqueous NaOH solution. The pH at the point of one-third neutralisation of the acid will be

• 5 + log 2 - log 3

• 5 - log 2

• 5 - log 3

• 5 - log 6

Considering the first dissociation which is more acidic and why -fumaric acid and maleic acid?

Calculate the number of H⁺ ions present in 1 mL of a solution whose pH is 10.

Addition of sodium acetate to 0.1 M acetic acid will cause

• increase in pH

• decrease in pH

• no change in pH

• change in pH that cannot be predicted

A catalyst is a substance which

• increases the equilibrium constant of the reaction

• increases equilibrium concentration of products

• does not alter the reaction mechanism

• changes the activation energy of the reaction

Which of the following acids has the smallest dissociation constant?

• CH₃CHFCOOH

• FCH₂CH₂COOH

• BrCH₂CH₂COOH

• CH₃CHBrCOOH