5 mL of 0.4 N NaOH is mixed with 20 mL of 0.1 N HCl.The pH of the resulting solution will be

• 7

• 8

• 5

• 6

The pH of the solution obtained by mixing 100 ml of a solution of pH = 3 with 400 mL of a solution of pH = 4 is

• 7 - log 2.8

• 4 - log 2.8

• 5 - log 2.8

• 3 - log 2.8

The equilibrium constant of the reaction

A (s) + 2B²⁺ (aq) $\rightleftharpoons$ A²⁺ (aq) + 2B (s);

E${}_{\mathrm{cell}}^{°} = 0.0295 \mathrm{V}\hspace{0.17em}\mathrm{is} \left[\frac{2.303 \mathrm{RT}}{\mathrm{F}} = 0.059\right]$

• 2 × 10²

• 3 × 10²

• 2 × 10⁵

• 10

An example for a neutral buffer is

• ammonium hydroxide and ammonium chloride

• acetic acid and sodium acetate

• acetic acid and ammonium hydroxide

• citric acid and sodium citrate

Conjugate base of H₂PO${}_4^{2-}$

• H₃PO${}_4^{-}$

• HPO${}_4^{2-}$

• H₃PO₄

• PO${}_4^{3-}$

For Cr₂O${}_7^{2-}$ + 14 H⁺ + 6e^- → 2Cr³⁺ + 7H₂O; E° = 1.33 V. At [Cr₂O${}_7^{2-}$] = 4.5 millimole, [Cr³⁺] = 15 millimole, E is 1.067 V. The pH of the solution is nearly equal to

• 2

• 3

• 5

• 4

Identify a species which is not a Bronsted acid but a Lewis acid

• BF₃

• H${}_3^{+}$O

• NH₃

• HCl

The pH of 10^-8 M HCl solution is

• 8

• 6.9586

• more than 8

• slightly more than 7

For the equilibrium,

CaCO₃ (s) $\rightleftharpoons$ CaO (s) + CO₂ (g) ; 

K_p = 1.64 atm at 1000 K

50 g of CaCO₃ in a 10 L closed vessel is heated to 1000 K. Percentage of CaCO₃ that remains unreacted at equilibrium is (Given, R = 0.082 L atm K^-1 mol^-1).

• 40

• 50

• 60

• 20

The acid strength of active methylene group in

I. CH₃COCH₂COOC₂H₅

II. CH₃COCH₂COCH₃

III. C₂H₅OOCCH₂COOC₂H₅

decreases as

• I > III > II

• I > II > III

• II > I > III

• III > I > II