The conjugate base of NH${}_2^{-}$ is

• NH₃

• NH^2-

• NH${}_4^{+}$

• N${}_3^{-}$

In an amino acid, the carboxyl group ionises at p${\mathrm{k}}_{{\mathrm{a}}_1}$ = 2.34 and ammonium, ion at p${\mathrm{k}}_{{\mathrm{a}}_2}$ = 9.6. The isoelectric point of the amino acid is at pH

• 5.97

• 11.94

• 2.34

• 9.60

The solubility product of Ag₂CrO₄ is 32 x 10^-12.What is the concentration of CrO₄^- ions in that solution?

• 2x 10^-4 M

• 16x 10^-4 M

• 8x 10^-4 M

• 8x 10^-8 M

Consider the water gas equilibrium reaction,

C (s) + H₂O (g) $\rightleftharpoons$ CO (g) + H₂ (g)

Which of the following statements is true at equilibrium?

• If the amount of C(s) is increased, less water would be formed

• If the amount of C(s) is increased, more CO and H₂ would be formed

• If the pressure on the system is increased by halving the volume, more water would be formed

• If the pressure on the system is increased by halving the volume, more CO and H₂ would be formed

The rate constant for forward reaction and backward reaction of hydrolysis of ester are 1.1 x10^-2 and 1.5 x10^-3 per minute respectively. Equilibrium constant for the reaction is

      ${\mathrm{CH}}_3{\mathrm{COOC}}_2{\mathrm{H}}_5 + {\mathrm{H}}_2\mathrm{O} \rightleftharpoons {\mathrm{CH}}_3\mathrm{COOH} + {\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}$

• 33.7

• 7.33

• 5.33

• 33.3

The reaction

           2A(g) + B(g) $\rightleftharpoons$3C(g) + D(g)

is begun with the concentrations of A and B both at an initial value of 1.00 M. When equilibrium is reached, the concentration of D is measured and found to be 0.25 M. The value for the equilibrium constant for this reaction is given by the expression

• [(0.75)³ (0.25)] $÷$ [(1.00)² (1.00)]

• [(0.75)³ (0.25)] $÷$ [(0.50)² (0.75)]

• [(0.75)³ (0.25)] $÷$ [(0.50)² (0.25)]

• [(0.75)³ (0.25)] $÷$ [(0.75)² (0.25)]

407.

20 mL of 0.2 M NaOH is added to 50 mL of 0.2 M acetic acid. The pH of this solution after mixing is (K_a=1.8x 10°)

• 4.5

• 2.3

• 3.8

• 4

A vessel at 1000 K contains CO₂ with a pressure of 0.5 atm. Some of the CO₂ is converted into CO on the addition of graphite. The value of K if the total pressure at equilibrium is 0.8 atm, is

• 1.8 atm

• 3 atm

• 0.3 atm

• 0.18 atm

For the reaction $2\mathrm{A} + \mathrm{B}\rightleftharpoons \mathrm{C}, ∆\mathrm{H} = \mathrm{x}$ cal, which one of the following conditions would favour the yield of C on the basis of Le-Chatelier principle?

• High pressure, high temperature

• Only low temperature

• High pressure, low temperature

• Only low pressure

For the reaction,

$2\mathrm{A}\left(\mathrm{g}\right) + {\mathrm{B}}_2\left(\mathrm{g}\right) \rightleftharpoons 2{\mathrm{AB}}_2\left(\mathrm{g}\right)$ the equilibrium constant, K_P at 300K is 16.0. The value of K_P for

${\mathrm{AB}}_2\left(\mathrm{g}\right) \rightleftharpoons \mathrm{A}\left(\mathrm{g}\right) + 1/2{\mathrm{B}}_2\left(\mathrm{g}\right) \mathrm{is}$

• 8

• 0.25

• 0.125

• 32