Mix Test

Result

Mix Test - 10

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

The compound benzophenone (C₆H₅COC₆H₅) does not react with

A
CH₃OH

B
NaHSO₃

C
HCN

D
NH₂OH

Solution

All aldehydes react with NaHSO₃ to form a white crystalline solid, bisulphite addition compound.
But ketones except for acetone and cyclohexanone do not react with NaHSO₃ due to stearic hindrance.
Question 2
1 / -0

If an allotropic form changes slowly to a stable form, it is called

A
enantiotropy

B
dynamic

C
monotropy

D
None of these

Solution
Question 3
1 / -0

The number of optical isomers of CH₃CH(OH)CH(OH)CHO is

A
zero

B
2

C
3

D
4

Solution
Question 4
1 / -0

Which of the following can act both as a Lewis acid and a Lewis base?

A
SOCl₂

B
H₂SO₄

C
OH^-

D
None of these

Solution
Question 5
1 / -0

The enthalpies of combustion at 25°C of H₂, cyclohexane (C₆H₁₂) and cyclohexene (C₆H₁₀) are -241 kJ/mole, -3920 kJ/mole and -3800 kJ/mole, respectively. The heat of hydrogenation of cyclohexene is

A
-121 kJ/mole

B
+121 kJ/mole

C
-242 kJ/mole

D
+242 kJ/mole

Solution

Given data:
(i) H₂ (g) + O₂(g) H₂O (l) = -241 kJ/mole
(ii) C₆H₁₀(g) + O₂(g) 6CO₂(g) + 5H₂O (l) = -3800 kJ/mole
(iii) C₆H₁₂(g) + 9O₂(g) 6CO₂(g) + 6H₂O (l) = -3920 kJ/mole

We have to calculate the enthalpy change for the reaction C₆H₁₀(g) + H₂(g) C₆H₁₂(g).
This equation can be obtained by:
Equation (ii) + Equation (i) - Equation (iii)

Carrying out the corresponding manipulations for s, we get
= (-3800 - 241 + 3920 kJ/mole) = -121 kJ/mole
Question 6
1 / -0

Which of the following statements is TRUE?

A
B-F bond is larger in BF₄^- than in BF₃.

B
FCl₃ exists whereas ClF₃ does not.

C
BF₃ is a stronger lewis acid than BBr₃.

D
NF₃ acts as donor molecule, while PF₃ shows little tendency to act as donor.

Solution

B-F bond is larger in BF₄^- than in BF₃. This is due to the fact that in BF₄^-, boron atom is sp³ hybridised, while in BF₃, boron atom is sp² hybridised and bond length decreases with increase in s-character, since s-orbital is smaller than p-orbital.
Question 7
1 / -0

If 3 g of helium diffuses from a container in 15 minutes, then the mass of sulphur dioxide diffusing from the same container under identical conditions over the same time interval will be

A
3 g

B
6 g

C
9 g

D
12 g

Solution

According to Graham's law of diffusion,

On solving we get,
w = 12 g
Question 8
1 / -0

A reversible chemical reaction (g) ⇌ 2NO (g) + (g) is carried at 400 K with = 77.2 kJ/mol
= 122 J/K/mol

Which of the following is the correct value (x) for of the reaction?

A
28.4 kJ/mol

B
27.2 kJ/mol

C
25.8 kJ/mol

D
25.6 kJ/mol

Solution

= – = 77.2 – = 28.4 kJ/mol
Question 9
1 / -0

What is the relation between K_p and K_c in the following reaction?

N₂(g) + 3H₂(g) 2NH₃(g)

A
K_p = K_c

B
K_p = K_c - RT

C
K_p = K_c/(RT)²

D
K_p = K_c/(RT)^-²

Solution

The relation between K_p and K_c is given as:
K_p = K_c(RT)^Δn
K_p = equilibrium constant in terms of partial pressure
(Its unit is 'atm'.)
K_c = equilibrium constant in terms of concentration (molarity)
R = ideal gas constant (0.082 atm.L/K.mol)
T = absolute temperature (570 K)
Δn = Σn products - Σn reactants
Δn = (2) - (3 + 1) = -2
Thus, for the formation of NH₃, the correct relation between K_pand K_c is:
K_p = K_c(RT)^-2 or K_p = K_c/(RT)²
Question 10
1 / -0

Why is the method of hydrogen preparation by action of cold water on potassium not preferred?

A
Because the rate of the reaction is very fast

B
Because the collection of hydrogen is difficult

C
Because the reaction is very violent

D
Because the reaction is endothermic

Solution

It is not preferred because the reaction is very violent and exothermic. The heat liberated ignites the hydrogen.
Question 11
1 / -0

In Antarctica, ozone depletion takes place due to the formation of which of the following compounds?

A
Acrolein

B
Peroxy acetyl nitrate

C
Chlorine nitrate

D
Formaldehyde

Solution

In Antarctica, ozone depletion takes place due to the formation of chlorine nitrate (ClONO₂).
Chlorine nitrate, with chemical formula ClNO₃ is an important atmospheric gas present in the stratosphere. It is an important sink of chlorine that contributes to the depletion of ozone.
Question 12
1 / -0

The oxidation state of central metal atom in 'lunar caustic' is

A
+1

B
+2

C
+3

D
+5

Solution

Silver nitrate (AgNO₃) is known as lunar caustic. The central metal in silver nitrate is nitrogen atom.
+ 1 + x + 3(-2) = 0
x - 5 = 0
x = +5
Hence, the oxidation state of N atom in silver nitrate is +5.
Question 13
1 / -0

For a first order reaction, the time taken to reduce the initial concentration by a factor of 1/4 is 10 min. The time required to reduce the initial concentration by a factor of 1/16 will be

A
10 min

B
20 min

C
30 min

D
40 min

Solution

For a first order reaction, time required to reduce the concentration by the same factor is constant.
Question 14
1 / -0

If k₁ and k₂ are the respective equilibrium constants for the reactions (I) and (II), where (I) is 2NO and (II) is NO, then

A
k₂ = k₁

B
k₂ =

C
k₁ = 2k₂

D
k₁ = k₂

Solution

On squaring k₂, we get
The right side of (k₂)²_ⁱs equal to k₁.
So, (k₂)² = (k₁)
Or k₂ =
Question 15
1 / -0

Which of the following aldehydes gives a red precipitate on reaction with Fehling solution?

A
Benzaldehyde

B
Salicylaldehyde

C
Acetaldehyde

D
None of these

Solution