Chemistry Test 208

Result

Chemistry Test 208

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

If 5.08 g of a cupric salt is dissolved in water and excess of KI is added to the solution, and the liberated I₂ requires 25 ml of M/5 Na₂S₂O₃, where it gets converted into S₄O₆^2-, then find the weight percentage of copper in the salt.

A
63.5%

B
4.25%

C
3.125%

D
1.25%

Solution
Question 2
4 / -1

The compound having the highest dipole moment is

A

B

C

D

Solution

Out of the given compounds, formaldehyde has the highest dipole moment due to the presence of highly electronegative oxygen atom.
Question 3
4 / -1

Which of the following is not a buffer solution?

A
0.8 M H₂S + 0.8 M KHS

B
2 M C₆H₅NH₂ + 2 M C₆H₅NH₃⁺Br^-

C
3 M H₂CO₃ + 3 M KHCO₃

D
0.05 M KClO₄ + 0.05 M HClO₄

Solution

A buffer solution is that which can resist a change in pH on addition of small amount of acid or base.

It is of two types:

(i) An acidic buffer (weak acid in excess + salt of its conjugate base)

(ii) A basic buffer (weak base in excess + salt of its conjugate acid)

KClO₄ + HClO₄ is not a buffer solution because it a mixture of a strong acid (HClO₄) and the salt of its conjugate base (KClO₄).

Note: All the other mixtures in the options are perfect buffers.
Question 4
4 / -1

A cell utilises the reaction Zn (s) + 2H⁺ (aq) Zn²⁺ (aq) + H₂ (g). Addition of H₂SO₄ to the cathode compartment will

A
lower E and shift the equilibrium to the left

B
lower E and shift the equilibrium to the right

C
increase E and shift the equilibrium to the right

D
increase E only

Solution

If H₂SO₄ is added to cathodic compartment, (towards reactant side), then Q decreases (due to increase in H⁺). Hence equilibrium is displaced towards right and E_cell increases.
Question 5
4 / -1

Which of the following series of reactions correctly represents the chemical relations related to iron and its compound?

A

B

C

D

Solution

Formation of Fe₃O₄ from Fe corresponds to the combustion of Fe and rest of the reactions correspond to the production of Fe by reduction of Fe₃O₄ in the blast furnace.
Question 6
4 / -1

Which of the following is formed when NaCl is heated with conc. H₂SO₄ and solid K₂Cr₂O₇?

A
Chromic sulphate

B
Chromous chloride

C
Chromyl chloride

D
Chromic chloride

Solution

NaCl is heated with conc. H₂SO₄ and solid K₂Cr₂O₇ to give chromyl chloride (orange red) vapours.
Question 7
4 / -1

b-particle is emitted in radioactivity by

A
conversion of proton to neutron

B
outermost orbit

C
conversion of neutron to proton

D
none of these

Solution

Since the nucleus does not contain b-particle, it is produced by the conversion of a neutron to a proton at the moment of emission.
Question 8
4 / -1

Which of the following alkenes will react faster with H₂ under catalytic hydrogenation conditions?

A

B

C

D

Solution

The following order of stability of alkenes has been derived from heat of hydrogenation

R₂C = CR₂ > R₂C = CHR > R₂C = CH₂ = trans-RCH=CHR > cis-RCH = CHR > RCH = CH₂ > CH₂= CH₂

The reactivity order is reverse of the stability order.
Question 9
4 / -1

When m-chlorobenzaldehyde is treated with 50% KOH solution, the product(s) obtained is/are

A

B

C

D

Solution
Question 10
4 / -1

Among cellulose, poly(vinylchloride), nylon and natural rubber, the polymer in which the intermolecular force of attraction is the weakest is

A
nylon

B
poly vinyl chloride

C
cellulose

D
natural rubber

Solution

Cellulose and nylon are fibres and their intermolecular forces are the strongest. Poly vinyl chloride is a thermoplastic, the intermolecular force in it is neither strong nor weak.

Natural rubber is an elastomer and the polymers are held by weak van der Waals forces.

Hence, natural rubber has the weakest forces.