For the reversible reaction : N 2 (g) + 3H 2 (g) 2NH 3 (g) + heat The equilibrium shifts in forward direction -

by increasing pressure and decreasing temperature

by increasing the concentration of N H 3 ( g )

by decreasing the concentration of N 2 ( g ) a n d H 2 ( g )

The conjugate bases of Bronsted acids H 2 O and HF are respectively:

H 3 O + and H 2 F + , respectively

OH - and H 2 F + , respectively

Chemistry - Equilibrium - Quiz-5

The ionization constant of benzoic acid is 6.46 x 10^–5 and Kc for silver benzoate is 2.5 x 10^–13. How many times silver benzoate is more soluble in a buffer of pH = 3.19 as compared to its solubility in pure water ?

0%

3.317
0%

9.5
0%

1000
0%

7.5

30 ml of 0.06 M solution of the protonated form of an anion acid methionine (H₂A⁺) is treated with 0.09 M NaOH. Calculate pH after addition of 20 ml of base. pKa₁, = 2.28 and pKa₂ = 9.2.

0%

5.5
0%

5.74
0%

9.5
0%

None

A certain acid–base indicator is red in acid solution and blue in basic solution 75% of the indicator is presentin the solution in its blue form at pH = 5. Calculate the pH at which the indicator shows 90% red form?

0%

3.56
0%

5.47
0%

2.5
0%

7.4

Ionisation constant of HA (weak acid) and BOH (weak base) are 3.0 x 10^–7 each at 298K. The percent degree of hydrolysis of BA at the dilution of 10L is :

0%

25
0%

50
0%

75
0%

40

Calculate the molar solubility of zinc tetrathiocyanato–N–mercurate (II) if its K_sp = 2.2 x 10^–7.

0%

0.00380
0%

0.000469
0%

0.0095
0%

0.0183

An acid–base indicator which is a weak acid has a pK_a value = 5.45. At what cocentration ratio of sodiumacetate to acetic acid would the indicator show a colour half–way between those of its acid and conjugate base forms? pK_a of acetic acid = 4.75. [log 2 = 0.3]

0%

4 : 1
0%

7 : 1
0%

5 : 1
0%

2 : 1

The indicator constant of phenolphthalein is approximately 10^–10. A solution is prepared by adding 100.01c.c. of 0.01 N sodium hydroxide to 100.00 c.c. of 0.01N hydrochloric acid. If a few drops of phenolphthalein are now added, what fraction of the indicator is converted to its coloured form?

0%

$\frac{2}{3}$
0%

$\frac{3}{4}$
0%

$\frac{1}{2}$
0%

$\frac{9}{11}$

A certain mixture of HCl and CH₃ – COOH is 0.1 M in each of the acids. 20 ml of this solution is titrated against 0.1M NaOH. By how many units does the pH change from the start to the stage when the HCl is almost completely neutralised? K_a for acetic acid = 1.8 x 10^–6.

0%

2.03
0%

0.775
0%

2.325
0%

3.172

A buffer solution is made by mixing a weak acid HA (K_a = 10^–6) with its salt NaA in equal amounts. What should be the amount of acid or salt that should be added to make 90 ml of buffer solution of buffer capacity. 0.1 ?

0%

10 milli moles
0%

22 milli moles
0%

9 milli moles
0%

11 milli moles

A sample of water has a hardness expressed as 80 ppm of Ca²⁺. This sample is passed through an ion exchange column and the Ca²⁺ is replaced by H⁺. What is the pH of the water after it has been so treated? [Atomic mass of Ca = 40]

0%

3
0%

2.7
0%

5.4
0%

2.4

In the reaction COCl₂(_g) $\overset{}{⇌}$ CO(g) + CI₂(g) at 550° , $K_{p} = 0.114$

,when the initial pressure of CO & Cl₂ are 250 and 280 mm of Hg respectively. The equilibrium pressure is found to be 380 mm of Hg. Calculate the degree of dissociation of COCl₂ at 1 atm. What will be the extent of dissociation, when N₂ at a pressure of 0.4 atm is present and the total pressure is 1 atm.

0%

0.32 and no change
0%

0.32 and 0.4
0%

0.4 and 0.3
0%

at the pressure,N₂ dissociation cannot take place

What is the value of pK_b (CH₃COOH^–) if $λ_{m}^{\infty}$ = 390 & $λ_{m}^{}$ = 7.8 for 0.04 of a CH₃COOH at 25°C

0%

() 9.3
0%

() 9.2
0%

() 4.7
0%

() 4.8

Assertion : It is difficult to distinguish the strengths of the strong acids such as

$HCl, H_{2} {SO}_{4}, {HNO}_{3}, HBr, Hl or {HClO}_{4}$ in dilute aqueous solutions.

Reason : In dilute aqueous solution all strong acids donate a proton to water and are essentially.

100% ionised to produce a solution containing $H_{3} O^{+}$ ions plus the anions of strong acid.

0%
If both the ssertion and the reason are true and the reason is a correct explanation of the assertion
0%
If oth the assertion and reason are true but the reason is not a correct explanation of the assertion
0%
If the assertion is true but the reason is false
0%
If both the assertion an reason are false

Assertion : 0.20 M solution of $NaCN$ is more basic than 0.20 M solution of $NaF$ .

Reason : 0.20 M solution of $NaCN$ is more basic than 0.20 M solution of ${CH}_{3} COONa .$

0%
If both the ssertion and the reason are true and the reason is a correct explanation of the assertion
0%
If oth the assertion and reason are true but the reason is not a correct explanation of the assertion
0%
If the assertion is true but the reason is false
0%
If both the assertion an reason are false

Assertion: A substance that can either act as an acid or a base is called ampholyte.

Reason: Bisulphide ion $({HS}^{-})$ and bicarbonate ion $({HCO}_{3}^{-})$ are ampholytes.

0%
If both the ssertion and the reason are true and the reason is a correct explanation of the assertion
0%
If oth the assertion and reason are true but the reason is not a correct explanation of the assertion
0%
If the assertion is true but the reason is false
0%
If both the assertion an reason are false

Which of the following statement is true if the reaction quotient, Q is equal to 1 ?

0%

$∆ G = 0$
0%

$∆ G^{\circ} = 0$
0%

$∆ S^{\circ} = 0$
0%

$∆ G = ∆ G^{\circ}$

The concentration of Ag⁺ ions in a saturated solution of Ag₂C₂O₄is $2.2 \times 10^{- 4} m o l L^{- 1}$ . The solubility product of Ag₂C₂O₄ is

0%

$2.66 \times 10^{- 12}$
0%

$4.5 \times 10^{- 11}$
0%

$5.3 \times 10^{- 12}$
0%

$2.42 \times 10^{- 8}$

The solubility of AgCl (s) with solubility product 1.6 x 10^-10 in 0.1 M NaCl solution would be

0%

$1.26 \times 10^{- 5} M$
0%

$1.6 \times 10^{- 9} M$
0%

$1.6 \times 10^{- 11} M$
0%

zero

A buffer solution is prepared in which the concentration of NH₃ is 0.30 M and the concentration of

N H_{4}^{+}

is 0.20 M. if the equilibrium constant, K_b for NH3 equals

1.8 \times 10^{- 5}

,what is the pH of this solution?
(log 2.7 = 0.43)

0%

9.43
0%

11.72
0%

8.73
0%

9.08

Which equilibrium reaction doesn't have equal values for K_c and K_p?

0%
$2NO(g) \rightleftharpoons N_2(g) + O_2(g)$
0%
$SO_2(g) + NO_2(g) \rightleftharpoons SO_3(g) + NO(g)$
0%
$H_2(g) + I_2(g) \rightleftharpoons 2HI (g)$
0%
$2C(s) + O_2(g) \rightleftharpoons 2CO_2(g)$

Which of the following molecular hydrides acts as a Lewis acid ?

0%

$N H_{3}$
0%

$H_{2} O$
0%

$B_{2} H_{6}$
0%

$C H_{4}$

The tendency of BF₃, BCl₃ and BBr₃ to behave as Lewis acid decreases in the sequence

0%

$B C l_{3} > B F_{3} > B B r_{3}$
0%

$B B r_{3} > B C l_{3} > B F_{3}$
0%

$B B r_{3} > B F_{3} > B C l_{3}$
0%

$B F_{3} > B C l_{3} > B B r_{3}$

Which of the following molecules acts as a Lewis acid?

0%

(CH₃)₃B
0%

(CH₃)₂O
0%

(CH₃)₃P
0%

(CH₃)₃N

The ionization constant of ammonium hydroxide is 1.77 x 10^-5 at 298 K. Hydrolysis constant of ammonium Chloride is

0%

5.65 x 10^-10
0%

6.50 x 10^-12
0%

5.65 x 10^-13
0%

5.65 x 10^-12

Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations :

A) $60 m L \frac{M}{10} H C I + 40 m L \frac{M}{10} N a O H$

B) $55 m L \frac{M}{10} H C I + 45 m L \frac{M}{10} N a O H$

C) $75 m L \frac{M}{5} H C I + 25 m L \frac{M}{5} N a O H$

D) $100 m L \frac{M}{10} H C I + 100 m L \frac{M}{10} N a O H$

pH of which one of them will be equal to 1?

0%

B
0%

A
0%

D
0%

C

The solubility of BaSO₄ in water is $2.42 \times 10^{- 3}$ g/ litre at 298 K. The value of the solubility product will be:

(Molar mass of BaSO₄ = 233 gmol^–1)

0%

$1.08 \times 10^{- 10} {mol}^{2} L^{- 2}$
0%

$1.08 \times 10^{- 12} {mol}^{2} L^{- 2}$
0%

$1.08 \times 10^{- 14} {mol}^{2} L^{- 2}$
0%

$1.08 \times 10^{- 8} {mol}^{2} L^{- 2}$

Which of the following conditions will favour maximum formation of the product in the reaction,
$A_{2} (g) + B_{2} (g) ⇋ X_{2} (g) ∆_{r} H = - X k J$ ?

0%

Low temperature and high pressure
0%
Low temperature and low pressure
0%
High temperature and high pressure
0%
High temperature and low pressure

Among the following the correct order of acidity is

0%

HClO < HClO₂< HClO₃< HClO₄
0%
HClO₂< HClO < HClO₃< HClO₄
0%
HClO₄< HClO₂< HClO < HClO₃
0%
HClO₃< HClO₄< HClO₂< HClO

At room temperature, MY and NY3, two nearly insoluble salts, have the same K_sp values of 6.2 x 10^-13 . The true statement regarding MY and NY₃ is:

0%

The molar solubility of MY in water is less than that of NY₃.
0%
The salts MY and NY₃ are more soluble in 0.5 M KY than in pure water

The addition of the salt of KY to a solution of MY and NY₃ will have no effect on their solubilities

Consider the nitration of benzene using mixed conc. H₂SO₄ and HNO₃. If a large amount of KHSO₄ is added to the mixture, the rate of nitration will be-

0%

Slower
0%
Unchanged

Doubled

Faster

If the equilibrium constant for $N_{2} (g) + O_{2} (g) ⇄ 2 NO (g)$ is K, the equilibrium constant for
$\frac{1}{2} N_{2} (g) + \frac{1}{2} O_{2} (g) ⇄ NO (g)$ will be,

0%

$K^{\frac{1}{2}}$
0%

$\frac{1}{2} K$
0%

K
0%

$K^{2}$

Aqueous solution of which of the following compounds is the best conductor of electric current?

0%

Acetic acid, $C_{2} H_{4} O_{2}$
0%

Hydrochloric acid, HCl
0%

Ammonia, $N H_{3}$
0%

Fructose, $C_{6} H_{12} O_{6}$

If the value of the equilibrium constant for a particular reaction is 1.6 x 10¹², when the system is in equilibrium, it will include

0%
All reactants
0%

Mostly reactants
0%
Mostly products

Similar amounts of reactants and products

For the reversible reaction :
N₂(g) + 3H₂(g) 2NH₃(g) + heat
The equilibrium shifts in forward direction -

0%

by increasing the concentration of $N H_{3} (g)$
0%

by decreasing the pressure
0%

by decreasing the concentration of $N_{2} (g) a n d H_{2} (g)$
0%

by increasing pressure and decreasing temperature

for a given exothermic reaction, K_p and K_p^’ are the equilibrium constants at temperatures T₁ and T₂respectively. Assuming that heat of reaction is constant in temperatures range between T₁ and T₂, it is readily observation that:

0%

$K_{p} > K_{p}^{'}$
0%

$K_{p} < K_{p}^{'}$
0%

$K_{p} = K_{p}^{'}$
0%

$K_{p} = \frac{1}{K_{p}^{'}}$

Which of these is least likely to act as Lewis base?

0%

F^–
0%

BF₃
0%

PF₃
0%

CO

The strongest acid among the following compounds is:

0%

HClO₃
0%
HClO₄

H₂SO₃

Equimolar solutions of the following substances were prepared separately. Which one of these will record the highest pH value?

0%

$B a C l_{2}$
0%

$A l C l_{3}$
0%

$L i C l$
0%

$B e C l_{2}$

What is the [OH^-] in the final solution prepared by mixing 20.0 mL of 0.050 M HCl with 30.0 mL of 0.10 M Ba(OH)₂ ?

0%

0.10 M
0%

0.40 M
0%

0.0050 M
0%

0.12 M

The dissociation constants for acetic acid and HCN at 25 °C are 1.5 x 10^-5and 4.5 x 10^-10, respectively. The equilibrium constant for the equilibrium,
CN^- + CH₃COOH ⇌ HCN + CH₃COO^-
would be

0%

$3.0 \times 10^{5}$
0%

$3.0 \times 10^{- 5}$
0%

$3.0 \times 10^{- 4}$
0%

$3.0 \times 10^{4}$

If the concentration of OH ' ions in the reaction

F e {(O H)}_{3} (s) ⇋ F e^{3 +} (a q) + 3 O H^{-} (a q)

is
decreased by

\frac{1}{4}

times, then equilibrium concentration of Fe³⁺ will increase by

0%

8 times
0%

16 times
0%

64 times
0%

4 times

The dissociation equilibrium of a gas AB₂ can be represented as
$2 A B_{2} (g) ⇋ 2 A B (g) + B_{2} (g)$
The degree of dissociation is ‘x’ and is small compared to 1. The expression relating the degree of dissociation (x) with equilibrium constant K_P and total pressure p is

0%

(2KP/p)
0%

(2Kp /p)^1/3
0%

(2KP/p)^1/2
0%

(KP/P)

The value of K_P1 and K_p2 for the reactions

X ⇋ Y + Z . . . . . . (i) a n d A ⇋ 2 B . . . . . . (i i)

are in ratio of 9 : 1. If degree of dissociation of X and. A be equal, then total pressure at equilibrium(i) and (ii) are in the ratio

0%

3 : 1
0%

1 : 9
0%

36 : 1
0%

1 : 1

The following equilibrium constants are given :
N₂ + 3H₂2NH₃; K₁
N₂ + O₂2NO; K₂
H₂ + 1/2O₂H₂O; K₃
The equilibrium constant for the oxidation of NH₃ by oxygen to give NO is:

0%

$K_{2} K_{3}^{3} / K_{1}$
0%

$K_{2} K_{3}^{2} / K_{1}$
0%

$K_{2}^{2} K_{3} / K_{1}$
0%

$K_{1} K_{2} / K_{3}$

Which one of the following orders correctly represents the increasing acid strengths of the given acids?

0%

$H O C l < H O C l O < H O C l O_{2} < H O C l O_{3}$
0%

$H O C l O < H O C l < H O C l O_{3} < H O C l O_{2}$
0%

$H O C l O_{2} < H O C l O_{3} < H O C l O < H O C l$
0%

$H O C l O_{3} < H O C l O_{2} < H O C l O < H O C l$

Which of the following pairs constitutes a buffer?

0%

$H N O_{2} a n d N a N O_{2}$
0%

$N a O H a n d N a C l$
0%

$H N O_{3} a n d N H_{4} N O_{3}$
0%

$H C l a n d K C l$

Which will make basic buffer:

0%

100 mL of 0.1 M HCl+100 mL of 0.1 M NaOH
0%

50 mL of 0.1 M NaOH+25 mL of 0.1 M CH₃COOH
0%

100 mL of 0.1 M CH₃COOH+100 mL of 0.1 M NaOH
0%

100 mL of 0.1 M HCl+200 mL of 0.1 M NH₄OH

pH of a saturated solution of $Ca {(OH)}_{2}$ is 9. The solubility product $(K_{sp})$ of $Ca {(OH)}_{2}$ is:

0%

$0.5 \times 10^{- 10}$
0%

$0.5 \times 10^{- 15}$
0%

$0.25 \times 10^{- 10}$
0%

$0.125 \times 10^{- 15}$

The conjugate bases of Bronsted acids H₂O and HF are respectively:

0%

H₃O⁺ and H₂F⁺, respectively
0%

OH^- and H₂F⁺, respectively
0%

H₃O⁺ and F^-, respectively
0%

OH^- and F^-, respectively

The solubility product of AgI at 25°C is 1.0 × 10^–16 mol²L^–2. The solubility if AgI in 10^–4 N solution of KI at 25°C is approximately :
(in mol L^–1)

0%
1.0 × 10^–8
0%

1.0 × 10^–16
0%

1.0 × 10^–12
0%

1.0 × 10^–10

0:0:1

Practice Chemistry Quiz Questions and Answers

0:0:1

Practice Chemistry Quiz Questions and Answers

Support mcqexams.com by disabling your adblocker.