Chemistry Test

Result

Chemistry Test - 4

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
4 / -1

When KMnO₄solution is added to oxalic acid solution, the decolourisation is slow in the beginning but becomes instantaneous after some time because:

A
CO₂ is formed as the product

B
Reaction is exothermic

C

D

Solution
Question 2
4 / -1

Photochemical smog can be suppressed by

A
Nitrogen oxides

B
Peroxyacetyl nitrate

C
Radical traps

D
Formaldehyde

Solution

Photochemical smog can be suppressed by radical traps. When the compounds are sprayed to the atmosphere, they generate free radicals which readily combine with free radical precursors of photochemical smog. Diethyl hydroxylamine has been found to possess smog inhibiting characteristics.
Question 3
4 / -1

A
A and B are equally stable

B
A is more stable than B

C
B is more stable than A

D
The predictable stability

Solution

Here, K₃[Fe(CN)₆] with dissociation constant 1.9 × 10¹⁷is more stable than K₄ [Fe(CN)₆] with dissociation constant 2.6 × 10³⁷. Higher is the dissociation constant lesser will be the stability of complex. So B is more stable than A .
Question 4
4 / -1

On adding a few drops of dilute HCl or Fecl₃to a freshly precipitated ferric hydroxide, a red-coloured colloidal solution is obtained. This phenomenon is called:

A
Peptisation

B
Dialysis

C
Protective action

D
Dissolution

Solution

Peptisation is the process of converting a precipitate into colloidal particles by adding a suitable electrolyte. The electrolyte is known as a peptizing agent. It is a stabilizing agent. The phenomenon of converting fresh mass into a colloidal state by the action of solute or solvent is known as peptization.

For example, the addition of a small amount of dil. HCl to stannic oxide precipitate gives a stable sol of stannic oxide.
Question 5
4 / -1

Alkali halids do not show Frenkel defect because:

A
Cations and anions have almost equal size

B
There is a large difference in size of cations and anions

C
Cations and anions have a low coordination number

D
Anions cannot be accommodated in voids

Solution

Frenkel defect is possible in the compounds in which the size of cations and anions are different. In this defect, the smaller ion comes to an interstitial place. In Alkali halides the size of cations and anions is almost equal. So the ion size is large and they cannot get into the interstitial site. So, these kinds of compounds do not show Frenkel defect.
Question 6
4 / -1

Two different first order reactions have rate constants k₁ and k₂ at T₁(k₁ > k₂) . If temperature is increased from T₁ to T₂ , then new constants become k₃ and k₄ respectively. Which among the following relations is correct?

A

B

C

D

Solution

As given, the temperature is increased from T₁ to T₂, then new constants become k₃and k₄respectively.

Rate constant increases with increase in temperature.
Question 7
4 / -1

Which of the following elements does not belong to the Carbon family?

A
Aluminium

B
Silicon

C
Plumbum

D
Stannum

Solution

Aluminium does not belong to the Carbon family.

Group 14 is the carbon family. The elements of Carbon family are the elements of group 14 They are carbon, Silicon, Germanium, stannum and plumbum. Their valence shell configuration is ns²np² and their valency is four. But aluminium belongs to group 13.

Group 3A (or IIIA) of the periodic table includes the metalloid boron (B), as well as the metals aluminum (Al), gallium (Ga), indium (In), and thallium (Tl).
Question 8
4 / -1

Which of the following group’s elements have smaller atomic radii?

A
Group 1 elements

B
Group 2 elements

C
Group 13 elements

D
All have the same atomic radii

Solution

Group 13 elements group’s elements have smaller atomic radii.

Group 13 elements have smaller atomic radii and ionic radii than those of alkaline earth metals and alkali metals due to the greater effective nuclear charge, atomic radii increases on going down the group with an abnormality at gallium.
Question 9
4 / -1

The co-ordination number and oxidation state of Cr in K₃ [Cr(C₂O₄)₃] are respectively:

A
6 and +3

B
3 and 0

C
4 and +2

D
3 and +3

Solution
Question 10
4 / -1

The pK_b value of ammonium hydroxide is 4.75. An aqueous solution of ammonium hydroxide is titrated with HCl. The pH of the solution at the point where half of the ammonium hydroxide has been neutralized will be:

A
9.25

B
8.25

C
7.50

D
4.75

Solution