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

MCQ 11 Mark

Dried fruit plastic bags sold in the market are filled with:

A
All of these
B
Hydrogen gas
✓
Nitrogen gas
D
Helium gas

Answer

Correct option: C.

Nitrogen gas

MCQ 21 Mark

An aqueous solution $\mathbf{A}$ turns phenolphthalein solution pink. On addition of an aqueous solution $\mathbf{B}$ to $\mathbf{A}$, the pink colour disappears. The following statement is true for solution $\mathbf{A}$ and $\mathbf{B}$.

✓
A has pH greater than 7 and B has pH less
B
A is strongly basic and B is a weak base. than 7.
C
A is strongly acidic and B is a weak acid.
D
A has pH less than 7 and B has pH greater than 7.

Answer

Correct option: A.

A has pH greater than 7 and B has pH less

(A) A has pH greater than 7 and B has pH less than 7.
Explanation:
A has pH greater than 7 and B has pH less than 7 .

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MCQ 31 Mark

You want to test for hardness of water but hard water is not available in the laboratory. Which of the following compounds may be dissolved in pure water to make it hard?
i. Hydrogen Carbonate of Sodium
ii. Sulphate of Magnesium
iii. Chloride of Calcium
iv. Carbonate of Sodium

A
(i) and (ii)
B
(ii) and (iii)
✓
(i) and (iv)
D
(iii) and (iv)

Answer

Correct option: C.

(i) and (iv)

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MCQ 41 Mark

Take three boiling tubes A, B and C. Pour some water in test tube A Put iron nails in it and cork it. Pour boiled distilled water in another test tube B and put iron nails in it. Add 1 ml of oil over it such that oil floats over it and prevents the air from entering. Take some iron nails in test tube C and put some anhydrous calcium chloride in it and cork it.
Leave all the three test tubes for one day and then observe.

In which test tube nail is rusted?

✓
Tube A
B
Tube B and C
C
Tube A and C
D
Tube B

Answer

Correct option: A.

Tube A

(A) Tube A
Explanation:
Iron nails get rusted in test tube A because both air and water are present in it. Iron nails do not get rusted in B because there is water but no air. In C, rusting will not take place because there is neither air nor water.

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MCQ 51 Mark

Match the following with the correct response:

Column A	Column B
(i) Welding	(a) Ethyl alcohol
(ii) Fuel in a spirit lamp	(b) Ester
(iii) Lime water turns milky	(c) Carbon dioxide
(iv) Fruity smell	(d) Ethyne and oxygen

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

Answer

Correct option: D.

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

(D) (i) - (d), (ii) - (a), (iii) - (c), (iv) - (b)
Explanation:
- The oxyacetylene welding process uses a combination of ethyne $\left(\mathrm{C}_{2} \mathrm{H}_{2}\right)$ and oxygen gas to provide a high-temperature flame. It is commonly used to permanently join mild steel.
- Alcohol meant for industrial purposes (fuel for spirit lamps) 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.
- Carbon dioxide turns lime water turns milky due to the formation of insoluble calcium carbonate.
- Esters have a fruity smell and are used in perfumes and cosmetics due to their characteristic odour.

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MCQ 61 Mark

The metals which are found in both free state as well as combined state are:

A
Gold and silver
B
Gold and platinum
C
Platinum and silver
✓
Copper and silver

Answer

Correct option: D.

Copper and silver

(D) Copper and silver
Explanation:
Copper and silver

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MCQ 71 Mark

Which of the given statement is true or false:
Statement A: Valeric acid is the common name of hexane.
Statement B: Glycerol is added in the manufacturing of soap.

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

Answer

Correct option: C.

Both the statements A and B are false

(C) Both the statements $A$ and $B$ are false
Explanation:
Valeric acid is another name for pentanoic acid. Soaps are sodium or potassium salts of long-chain fatty acids. When triglycerides in fat/oil react with aqueous NaOH or KOH , they are converted into soap and glycerol.

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MCQ 81 Mark

Which one of the following statements is not correct?

A
Some of the metals react with acids to give salt and hydrogen gas.
B
Generally, all metal carbonates react with acids to give salt, water and carbon dioxide.
✓
All metal oxides react with water to give salt and hydrogen gas.
D
Some non-metal oxides react with water to form acids.

Answer

Correct option: C.

All metal oxides react with water to give salt and hydrogen gas.

(C) All metal oxides react with water to give salt and hydrogen gas.
Explanation:
All metal oxides react with water to give salt and hydrogen gas.

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