M.C.Q-[Che-1M]

MCQ 11 Mark

Which of the given statement is correct or wrong:
Statement A: Oxyacetylene flame is used for welding purposes.
Statement B: Ethyne reacts with HCl in the presence of $\mathrm{HgCl}_{2}$ to form vinyl chloride.

A
Neither statement $A$ nor statement $B$ is true.
✓
Both the statements A and B are true.
C
Statement B is true; Statement A is false.
D
Statement A is true; Statement B is false.

Answer

Correct option: B.

Both the statements A and B are true.

(B) Both the statements A and B are true.
Explanation:
- The oxyacetylene flame is used for welding purposes. The oxyacetylene welding process uses a combination of oxygen and acetylene ( $\mathrm{C}_{2} \mathrm{H}_{2}$ ) gas to provide a high-temperature flame. It is commonly used to join mild steel permanently.
- Ethyne $\left(\mathrm{C}_{2} \mathrm{H}_{2}\right)$ reacts with HCl in the presence of $\mathrm{HgCl}_{2}$ to from vinyl chloride or chloroethane $\mathrm{H}_{2} \mathrm{C}=\mathrm{CHCl}$. This colourless compound is an important industrial chemical. It is chiefly used to produce polyvinyl chloride (PVC).

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MCQ 21 Mark

Washing soda is a

A
neutralized salt
B
acidic salt
✓
basic salt
D
amphoteric salt

Answer

Correct option: C.

basic salt

(C) basic salt
Explanation:
Washing soda is a is basic salt because washing soda is an alkali salt. Alkali salts or basic salt are salts that are the product of the neutralization of a strong base and a weak acid. As it is strongly basic it is so-called basic salt.

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MCQ 31 Mark

A hydrocarbon with molecular formula $\mathrm{C}_{4} \mathrm{H}_{10}$ has:

A
10 covalent bonds
B
7 covalent bonds
C
6 covalent bonds
✓
13 covalent bonds

Answer

Correct option: D.

13 covalent bonds

(D) 13 covalent bonds
Explanation:Butane $\mathrm{C}_{4} \mathrm{H}_{10}$ has $3 \mathrm{C}-\mathrm{C}$ covalent bonds and $10 \mathrm{C}-\mathrm{H}$ covalent bonds. Thus, it has 13 covalent bonds.

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MCQ 41 Mark

Aqueous solutions of zinc sulphate and iron sulphate were taken in test tubes I and II by four students A, B, C and D . Metal pieces of iron and zinc were dropped in the two solutions and observations made after several hours were recorded in the form of table as given below:

The correct reporting has been made in observations:

A
Student B
B
Student A
✓
Student C
D
Student D

Answer

Correct option: C.

Student C

(C) Student C
Explanation:
Fe + ZnSO₄ → No reaction
It is because iron is less reactive than Zinc.
$\mathrm{Zn}+\mathrm{FeSO}_{4} \rightarrow \mathrm{ZnSO}_{4}+\mathrm{Fe}$
The solution becomes colourless and black iron gets deposited.

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MCQ 51 Mark

Match the following with the correct response:

Column A	Column B
(i) Addition reaction	(a) Hydrogenation
(ii) Substitution reaction	(b) Methanol
(iii) Denaturation	(c) Carbon tetrachloride
(iv) Esterification	(d) Ethyl ethanoate

A
(i) - (b), (ii) - (d), (iii) - (a), (iv) - ©
✓
(i) - (a), (ii) - (c), (iii) - (b), (iv) - (d)
C
(i) - (c), (ii) - (b), (iii) - (d), (iv) - (a)
D
(i) - (d), (ii) - (a), (iii) - (c), (iv) - (b)

Answer

Correct option: B.

(i) - (a), (ii) - (c), (iii) - (b), (iv) - (d)

(B) (i) - (a), (ii) - (c), (iii) - (b), (iv) - (d)
Explanation:
- Hydrogenation is an addition reaction. The addition of hydrogen to an unsaturated hydrocarbon to obtain a saturated hydrocarbon is called hydrogenation.
- Carbon tetrachloride is a product of a substitution reaction - a characteristic property of saturated hydrocarbons.
- Alcohol meant for industrial purposes is made unfit for human consumption by adding small amounts (about $5 \%$ ) of methanol to alcohol. The mixture is known as denatured spirit or denatured alcohol.
- Ethyl ethanoate is a product of esterification.
$\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH} \rightarrow \mathrm{CH}_{5} \mathrm{COOC}_{2} \mathrm{H}_{5}+\mathrm{H}_{2} \mathrm{O}$

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MCQ 61 Mark

What happens when ammonia reacts with hydrogen chloride? $\mathrm{NH}_{3}+\mathrm{HCl} \rightarrow$ ?

A
Both $\mathrm{H}_{2}$ and $\mathrm{NH}_{4} \mathrm{Cl}$
B
$\mathrm{Cl}_{2}$ gas is evolved.
C
$\mathrm{H}_{2}$ gas is evolved
✓
$\mathrm{NH}_{4} \mathrm{Cl}$ is formed

Answer

Correct option: D.

$\mathrm{NH}_{4} \mathrm{Cl}$ is formed

(D) $\mathrm{NH}_{4} \mathrm{Cl}$ is formed
Explanation: Ammonium chloride is formed when ammonia reacts with hydrogen chloride. It is a combination reaction.
$\mathrm{NH}_{3}(\mathrm{~g})+\mathrm{HCl}(\mathrm{g}) \rightarrow \mathrm{NH}_{4} \mathrm{Cl}(\mathrm{s})$

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MCQ 71 Mark

Which of the given statement is true about Sodium carbonate:
A. It is a transparent crystalline white solid
B. It has the chemical formula $\mathrm{Na}_{2} \mathrm{CO}_{3} \cdot 10 \mathrm{H}_{2} \mathrm{O}$
C. It gives acidic solution when dissolved in water
D. It is prepared by reacting with chlorine

A
C and D
B
A and C
✓
A and B
D
All of these

Answer

Correct option: C.

A and B

(C) A and B
Explanation:
(C) and (D) are incorrect because the solution of washing soda in water is alkaline which turns red litmus blue. And washing soda is prepared from sodium chloride.

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