At radioactive equilibrium, the ratio between two atoms of radioactive elements A and B is 3.1 x 10⁹ : 1. If the half-life period of A is 2 x 10¹⁰ yrs, then the half-life of B is

• 9.54 yrs

• 2.14 yrs

• 3.29 yrs

• 6.45 yrs

The dissociation equilibrium of a gas AB₂ can be represented as

2AB₂ (g) $\rightleftharpoons$2AB (g) + B₂(g)

The degree of dissociation is 'x' and is small compared to 1. The expression relating the degree of dissociation (x) with equilibrium constant KP and total pressure p is

• $\frac{2K_p}{p}$

• ${\left(\frac{2K_p}{p}\right)}^{\frac{1}{3}}$

• ${\left(\frac{2K_p}{p}\right)}^{\frac{1}{2}}$

• $\frac{K_p}{p}$

A buffer solution is prepared in which the concentration of NH₃ is 0.30 M and the concentration of N${\mathrm{H}}_4^{+}$ is 0.20 M. If the equilibrium constant, K_b for NH₃ equals 1. 8 x 10^-5, what is the pH of this solution? (log 2. 7 =0. 43).

• 9.43

• 11.72

• 8.73

• 9.08

Which of the following is least likely to behave as Lewis base?

• NH₃

• BF₃

• OH^-

• H₂O

For the reaction, N₂(g) + O₂(g) $\rightleftharpoons$ 2NO (g), the equilibrium constant is K₁. The equilibrium constant is K₂ for the reaction, 2NO(g) + O₂)g) $\rightleftharpoons$ 2NO₂(g). What is K for the reaction, NO₂(g) $\rightleftharpoons$$\frac{1}{2}{\mathrm{N}}_2 \left(\mathrm{g}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right)$ ?

• $\frac{1}{4{\mathrm{K}}_1{\mathrm{K}}_2}$

• ${\left[\frac{1}{{\mathrm{K}}_1{\mathrm{K}}_2}\right]}^{\frac{1}{2}}$

• $\frac{1}{{\mathrm{K}}_1{\mathrm{K}}_2}$

• $\frac{1}{2{\mathrm{K}}_1{\mathrm{K}}_2}$

In an amino acid, the carboxyl group ionises at pK_a = 2.34 and ammonium ion at pK_a2 = 9.60. The isoelectric point of the amino acid is at pH

• 4.32

• 3.34

• 9.46

• 5.97

What percentage of $\mathrm{\beta }$-D-(+-glucopyranose is found at equilibrium in the aqueous solution?

• 64%

• 36%

• $\approx$100%

• $\approx$50%

498.

$∆\mathrm{H} \mathrm{and} ∆\mathrm{S}$ for the rreaction,

Ag₂O(s) $\to$2Ag(s) + $\frac{1}{2}$ O₂ (g) are 30.56 kJ mol^-1 and 66.00 JK^-1 mol^-1 respectively. The temperature at which the free energy change for the reaction will be zero is

• 3528 K

• 463 K

• 73 K

• 144 K

Ig Ag⁺ + 2NH₃ $\rightleftharpoons$Ag (NH_{3${)}_2^{+}$ ; K1} = 1.7 x 10⁷

Ag⁺ + Cl^- $\rightleftharpoons$ AgCl; K₂ = 5.4 x 10⁹

Then, for AgCl + 2NH₃ $\rightleftharpoons$[Ag(NH₃)₂]⁺ + Cl^- equilibrium constant will be

• 0.68 x 10^-3

• 5.2 x 10^-17

• 0.31 x 10^-2

• 3.1 x 10^-2

For the following equilibrium (omitting charges)

I. M + Cl $\to$ MCl, K_eq = $\mathrm{\beta }$₁

II. MCl + Cl $\to$MCl₂, K_eq = $\mathrm{\beta }$₂

III. MCl₂ +Cl $\to$ MCl₃ ,K_eq  = $\mathrm{\beta }$₃

IV. M + 3Cl $\to$ MCl₃ , K_eq = K

then relationship between K, ${\mathrm{\beta }}_1 , {\mathrm{\beta }}_{2 }\mathrm{and} {\mathrm{\beta }}_3$

• K = ${\mathrm{\beta }}_1{\mathrm{\beta }}_2{\mathrm{\beta }}_3$

• $\log \mathrm{K} = \log {\mathrm{\beta }}_1 + \log {\mathrm{\beta }}_2 + \log {\mathrm{\beta }}_3$

• ${\mathrm{p}}_{\mathrm{k}} = {\mathrm{p}}_{{\mathrm{\beta }}_1} + {\mathrm{p}}_{{\mathrm{\beta }}_2 }+ {\mathrm{p}}_{{\mathrm{\beta }}_3}$

• All of the above