Chemistry Test 220

Result

Chemistry Test 220

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

Identify the least stable ion.

A
Li^-

B
Be^-

C
B^-

D
C^-

Solution

This option is correct because the electronic configuration of Be = 1s² 2s².

Therefore, the electronic configuration of Be^- = 1s² 2s² 2p¹.

So, the stable electronic configuration of Be has broken up and it is highly unstable.
Question 2
4 / -1

The reaction, 2SO_2(g) + O_2(g) → 2SO₃(g) is carried out in a 1 dm³ vessel and a 2 dm³ vessel, separately. The ratio of the reaction velocities, respectively, will be

A
1 : 8

B
1 : 4

C
4 : 1

D
8 : 1

Solution
Question 3
4 / -1

Cyanide process is used for the extraction of

A
barium

B
aluminium

C
boron

D
gold

Solution

Gold and silver are extracted from their native ores by MacArthur-Forrest cyanide process.

4Au(s) + 8NaCN(aq) + O₂(g) + 2H₂O(l) → 4Na[Au(CN)₂](aq) + 4NaOH(aq)

2Na[Au(CN)₂](aq) + Zn(s) → Na₂[Zn(CN)₄] + 2Au
Question 4
4 / -1

KO₂ (potassium superoxide) is used in oxygen cylinders in space and submarines because it

A
absorbs CO₂ and increases O₂ content

B
eliminates moisture

C
absorbs CO,

D
produces ozone

Solution

Potassium superoxide is widely used as a CO₂ scrubber and O₂ generator in spacecrafts and submarines.

The following reaction takes place:

4KO₂ + 2CO₂ → 2K₂CO₃ + 3O₂
Question 5
4 / -1

Which of the following dissolves in water but does not give any oxyacid solution?

A
SO₂

B
OF₂

C
SCI₄

D
SO₃

Solution

In OF₂, fluorine has negative oxidation state due to high electronegativity. Therefore, OF₂ dissolves in water but does not give any oxyacid solution because unlike other halogens, fluorine cannot acquire a positive oxidation state. In oxyacids of halogens, all halogen atoms have positive oxidation states.

SO₂, SCI₄ and SO₄ give oxyacid solutions in water and acquire positive oxidation states as shown below.
Question 6
4 / -1

The actinoids exhibit more number of oxidation states in general than the lanthanoids. This is because

A
the 5f orbitals extend further from the nucleus than the 4f orbitals

B
the 5f orbitals are more buried than the 4f orbitals

C
there is a similarity between 4f and 5f orbitals in their angular part of the wave function

D
the actinoids are more reactive than the lanthanoids

Solution

As the distance between the nucleus and 5f orbitals (in actinides) is more than the distance between the nucleus and 4f orbitals (lanthanides), therefore the hold of nucleus on valance electron decreases in actinides. For this reason, the actinoids exhibit more number of oxidation states in general.
Question 7
4 / -1

The correct stability order of the above species is

A
(II) > (IV) > (I) > (III)

B
(I) > (II) > (III) > (IV)

C
(II) > (I) > (IV) > (III)

D
(I) > (III) > (II) > (IV)

Solution

Stability of the carbocations depends upon the number of α-hydrogen, which can undergo hyperconjugation, as well as on their ability to exhibit resonance. Greater the number of α-hydrogen, the more will be the stability of the carbocation.
Question 8
4 / -1

A

B

C

D

Solution

Ketones, with Grignard reagent, give tertiary alcohols. Here, 3°-alcohol obtained cyclises to give product given in option (3). The reactions involved are as follow
Question 9
4 / -1

Benzoylacetonato beryllium exhibits isomerism of which of the following types?

A
Structural

B
Geometrical

C
Optical

D
Conformational

Solution

Benzoylacetonato beryllium or bis (benzoylacetonato) beryllium (II) complex exhibits optical isomerism as shown below.
Question 10
4 / -1

Aqueous solution of potassium acetate is electrolysed. Possible organic product(s) is/are

A
CH₃CH₃

B
CH₃COOCH₃

C
CH₃CH₂CH₂CH₃

D
Both (1) and (2)

Solution