A chemist wishes to prepare a buffer solution of pH = 2.90 that efficiently resists a change in pH yet contains only small concentration of buffering agents which one of the following weak acid along with its salt would be best to use 

• m-chlorobenzoic acid (pK_a = 3.98)

• Acetoacetic acid (pK_a = 3.58)

• 2 5-dihydrobenzoic acid (pK_a = 2.97)

• p-chlorocmanic acid (pK_a = 4.41)

NaOH is a strong base. What will the be pH of 5.0 × 10^-2 M NaOH solution? (log 2 = 0.3)

• 14.00

• 13.70

• 13.00

• 12.70

The equilibrium constants of the reactions

${\mathrm{SO}}_2\left(\mathrm{g}\right) + \frac{1}{2}{\mathrm{O}}_2\left(\mathrm{g}\right) \rightleftharpoons {\mathrm{SO}}_3\left(\mathrm{g}\right)$ and $2{\mathrm{SO}}_2\left(\mathrm{g}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right) \rightleftharpoons 2{\mathrm{SO}}_3\left(\mathrm{g}\right)$ are K₁ respectively. The relationship between K₁ and K₂ will be

• ${\mathrm{K}}_1^2=$K₂

• K₂ = √K₁

• K₁= K₂

• ${\mathrm{K}}_2^3 = {\mathrm{K}}_1$

The value of K_c for the dissociation reaction, H₂ (g) $\rightleftharpoons$ 2H (g) is 1.2 × 10^-42

This equilibrium mixture contains mainly

• H₂ (g)

• H (g) atom

• 1.1 M mixture of H₂ and H

• 1.2 M mixture of H₂ and H

Among the following, the equilibrium which is not affected by an increase in pressure is

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

• 3Fe(s) + 4H₂O (g) $\rightleftharpoons$Fe₃O₄ (s) + 4H₂(g)

• 2SO₃(g) $\rightleftharpoons$2SO₂(g) + O₂ (g)

• H₂ (g) + I₂(s) $\rightleftharpoons$2Hi(g) 

K_sp of CaSO₄ is 4 × 10^-12. CaSO₄ is precipitated on mixing equal volumes of the following solutions.

• 3 × 10^-10 M CaCl₂ and 3 × 10^-6 M (NH₄)₂SO₄

• 4 × 10^-6 M CaCl₂ and 3 × 10^-6 M (NH₄)₂SO₄

• 6 × 10^-6 M CaCl₂ and 3 × 10^-16 M (NH₄)₂SO₄

• In all the above cases

What is pH of 2 x 10^-8 molar HCl solution? Here, log 2 = 0.301 and log 3 = 0.477.

• 6.92

• 9.5

• 5.4

• 7.7

Which one of the following species acts as both Bronsted acid and base?

• H₂PO${}_2^{-}$

• HPO${}_3^{2-}$

• HPO${}_4^{2-}$

• All of these

The reaction, SO₂ + O₂ → 2SO₂ + Heat.

The equilibrium reaction proceeds in forward direction by

• addition of O₂

• removal of O₂

• addition of inert gas

• cannot proceed

Which is soluble in NaNO₃ and dil. HCl mixture and forming salt?

• (CH₃)₃CNH₂

• (CH₃)₂CHNH₂

• (CH₃)₂NH

• (CH₃)₃N