Chemistry Test

Result

Chemistry Test - 25

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

In the following reaction, predict the compounds \(X\) and \(Y\).

A

B

C

D

Solution

The complete reaction is as follows:
Question 2
4 / -1

Allene (C₃H₄) contains

A
one double bond, one triple bond and one single bond

B
one triple and two double bonds

C
two triple and one double bonds

D
two double and four single bonds

Solution

An allene is a compound in which one carbon atom has double bonds with each of its two adjacent carbon centres. It contains two double bonds and four single bonds.
Question 3
4 / -1

The rate of a reaction can be increased in general by all the factors except by

A
using a catalyst

B
increasing temperature

C
increasing the activation energy

D
increasing the concentration of reactant

Solution

This option is correct because, it is the minimum amount of energy required by reactant molecule to get converted into product. Hence this option is correct.
Question 4
4 / -1

Highly reactive metals (like K, Na, Ca, Mg, Al) are extracted by

A
reducing carbon

B
electrolysis of their molten chlorides or oxides

C
heating their sulphide ore in air

D
Both (1) and (2)

Solution

Highly reactive metals are extracted by the electrolysis of their molten chlorides or oxides.

For example, when molten sodium chloride is electrolysed, sodium metal is obtained on cathode and chlorine gas is obtained at anode.

\(2 \mathrm{Na}^{+}+2 \mathrm{e}^{-} \rightarrow 2 \mathrm{Na}\)

\(2 \mathrm{Cl}^{-}-2 \mathrm{e} \rightarrow \mathrm{Cl}_{2}\)
Question 5
4 / -1

Acetaldehyde gives orange coloured precipitate on treatment with

A
2, 4-DNP

B
NH₂OH

C
NaHSO₃

D
NaOH

Solution

Acetaldehyde gives orange coloured precipitate on treatment with 2, 4-DNP.
Question 6
4 / -1

In which of the following properties is hydrogen different from halogens?

A
Electronic configuration

B
Ionisation enthalpy

C
Oxidation state

D
Atomicity

Solution

Electronic configuration of halogens is ns²np⁵, while hydrogen has half-filled valence shell, i.e. ns1.

Hydrogen and halogens both have a high ionisation energy.

Hydrogen can exhibit -1 oxidation state like the halogens.

Hydrogen as well as halogens occur as diatomic molecules.
Question 7
4 / -1

Which of the following is the correct order of decreasing S_N2 reactivity?

A
R₃CX > R₂CHX > RCH₂X

B
R₂CHX > R₃CX > RCH₂X

C
RCH₂X > R₃CX > R₂CHX

D
RCH₂X > R₂CHX > R₃CX

Solution

Rate of SN² reaction is based on the steric hindrance and the electron density at the carbon attached to halogen.

It follows the order: RCH₂X > R₂CHX > R₃CX
Question 8
4 / -1

Clemmensen reduction of a ketone is carried out in the presence of

A
H₂with Pd as catalyst

B
glycol with KOH

C
LiAlH₄in ether

D
Zn-Hg with HCl

Solution

Clemmensen reduction is the reduction of carbonyl groups of aldehydes and ketones to methylene groups with amalgamated zinc and concentrated HCl.
Question 9
4 / -1

The unwanted impurities like sand, rocky material, lime stone, mica etc present in an ore called

A
Flux

B
slag

C
gangue

D
None of these.

Solution

In mining, gangue is the commercially worthless material that surrounds, or is closely mixed with, a wanted mineral in an ore deposit. The separation of mineral from gangue is known as mineral processing.
Question 10
4 / -1

Which of the following statements is incorrect?

A
Pure aluminium oxide is obtained by heating aluminium hydroxide.

B
Cryolite lowers down the melting temperature of bauxite in the electrolyte cell for extraction of aluminium.

C
Carbonate ores are converted into oxides by roasting ore in air.

D
Mercury cannot be produced by roasting the ore cinnabar in air.

Solution

Carbonate ores are converted into oxides through the process of calcination.