Chemistry Test 69

Result

Chemistry Test 69

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

[Co(H₂O)₆]²⁺has three unpaired electrons and has a calculated value of magnetic moment as 3.87 BM, which is quite different from the experimental value of 4.40BM. This is due to:

A
An increase in the number of unpaired electrons

B
Some contribution of the total orbital motion of the electron to the magnetic moment

C
Change in the orbital spin of the electron

D
d-d transition

Solution

Where n= Number of unpaired e⁻

As the t_2g orbital is unsymmetrically filled.

Thus, due to orbital motion contribution, the magnetic moment goes with the value 4.40BM.

Hence, the correct option is (B).
Question 2
4 / -1

The increasing order of basicity of the following compounds is:

A
(b) < (a) < (c) < (d)

B
(b) < (a) < (d) < (c)

C
(d) < (b) < (a) < (c)

D
(a) < (b) < (c) < (d)

Solution
Question 3
4 / -1

0.1 mole of N₂O_4( g) was sealed in a tube under one atmospheric conditions at 25^∘C. Calculate the number of moles of NO_2(g) present, if the Equlibrium N₂O_4(g)⇌ 2NO_2(g)(K_p=0.14) is reached after some time

A
1.8 × 10²

B
2.8 × 10²

C
3.4 × 10^-2

D
2.8 × 10^-2

Solution
Question 4
4 / -1

Directions For Questions

Two solutions of a substance (non electrolyte) are mixed in the following manner:

480 mL of 1.5M first solution +520 mL of 1.2M second solution.

...view full instructions

What is the molarity of the final mixture?

A
2.70 M

B
1.344 M

C
1.50 M

D
1.20 M

Solution

For mixing solutions of same substances, final molarity is found using this formula.
Question 5
4 / -1

The molecular shapes of SF₄, CF₄ and XeF₄are:

A
The same with 2, 0 and 1 lone pairs of electrons on the central atom respectively

B
The same with 1, 1 and 1 lone pair of electrons on the central atoms respectively

C
Different with 0, 1 and 2 lone pairs of electrons on the central atom respectively

D
Different with 1, 0 and 2 lone pairs of electrons on the central atom respectively

Solution

SF₄ (sp³d, trigonal bipyramidal with one equatorial position occupied by 1 lone pair), CF₄ (sp³, tetrahedral, no lone pair), XeF₄ (sp³d₂, square planar, two lone pairs).

Hence, the correct option is (D).
Question 6
4 / -1

Which of the following is an example of Baeyer-Villiger rearrangement?

A

B

C

D

Solution

The treatment of ketones with peracids (RCOOOH) or hydrogen peroxide gives esters by insertion of oxygen. The reaction is called Baeyer-Villiger rearrangement or Baeyer-Villiger oxidation.

Hence, the correct option is (B).
Question 7
4 / -1

The percentage by volume of C₃H₈in a mixture of C₃H₈, CH₄ and CO is 36.5. Calculate the volume of CO₂ produced when 100ml of the mixture is burnt in excess of O₂.

A
175ml

B
173ml

C
150ml

D
123ml

Solution
Question 8
4 / -1

The species, having bond angles of 120° is:-

A
CIF₃

B
NCl₃

C
BCl₃

D
PH₃

Solution

BCl₃ is sp₂ hybridized and is trigonal planar in shape and hence the bond angle is 120°.

Hence, the correct option is (C).
Question 9
4 / -1

Hard water when passed through ion exchange resin containing R'COOH groups, becomes free from:

A
CI^-

B

C
H₃O⁺

D
Ca²⁺

Solution

An ion exchange resin containing R - COOH group exchange cations like Ca²⁺, Mg²⁺, Na, Fe²⁺ with H⁺ when hard water is passed through it. This resin is called cation exchange resin.
Question 10
4 / -1

Chemical A is used for water softening to remove temporary hardness, A reacts with Na₂CO₃ to generate caustic soda. When CO₂ is bubbled through A, it turns cloudy. What is the chemical formula of A?

A
CaCO₃

B
CaO

C
Ca(OH)₂

D
Ca(HCO₃)₂

Solution

The chemical A is calcium hydroxide (Ca(OH)₂). It is used for water softening to remove temporary hardness. It reacts with sodium carbonate to form caustic soda.