SCIENCE AND TECHNOLOGY – Math-Science Dears

SCIENCE AND TECHNOLOGY – Chapter 15

Acids, Bases and Salts

1 / 15

Copper sulphate crystals when heated strongly, lose their water of crystallization to give anhydrous copper sulphate accompanied by a change in color from:

Blue to green

Blue to white

Blue to sky blue

Blue to grey

2 / 15

Some fruits like mango, lemon, raw grapes, orange, etc., have a sour taste due to the presence of:

Acetic acid

Citric acid

Lactic acid

Oxalic acid

3 / 15

Zinc granules on treating with an acid X, form the zinc sulphate (ZnSO4) salt along with the evolution of a gas Y which burns with a pop sound when brought near to a burning candle. Identify the acid X and gas evolved Y.

X- Sulphuric acid and Y- Oxygen gas

X- Hydrochloric acid and Y- Oxygen gas

X- Sulphuric acid and Y- Hydrogen gas

X- Hydrochloric acid and Y- Hydrogen gas

4 / 15

The figure given below represents the experiment carried out between conc. sulphuric acid and sodium chloride, which react with each other to form HCl gas.

Blue litmus paper is brought near the mouth of the delivery tube to check the presence of HCl acid but no change is observed in the color of litmus paper because:

The litmus paper used is dry

The litmus paper used is moist

Blue litmus paper does not change its color with an acid

The litmus paper is kept very close to the mouth of the delivery tube

5 / 15

Which of the following phenomena occur, when a small amount of acid is added to water?
i. Ionisation
ii. Neutralisation
iii. Dilution
iv. Salt formation

(i) and (ii)

(i) and (iii)

(ii) and (iii)

(ii) and (iv)

6 / 15

Which of the following indicators turn red in an acidic solution?
i. Phenolphthalein
ii. Litmus
iii. Turmeric
iv. Methyl orange
Choose the correct option:

(i) and (ii)

(ii) and (iii)

Only (ii)

(ii) and (iv)

7 / 15

Dilute acid does not produce carbon dioxide on being treated with:

Marble

Lime

Baking soda

Limestone

8 / 15

The sample of soil from a particular place was tested for its pH value. It came out to be 5. Which one of the following should be added to the soil to make it suitable for the plant growth?
i. Calcium chloride
ii. Calcium Hydroxide
iii. Calcium oxide
Choose the correct option:

Both (i) and (ii)

Both (ii) and (iii)

Only (i)

Only (iii)

9 / 15

Identify the products of the following reaction:

Calcium hydrogencarbonate and chlorine gas

Calcium chloride and water

Calcium oxide, carbon dioxide and water

Calcium chloride, carbon dioxide and water

10 / 15

An ant’s sting can be treated with …………which will neutralise the effect of the chemical injected by the ant’s sting into our skin.
Choose the correct option from the following to be filled in the blank space:

Methanoic acid

formic acid

Baking soda

Caustic soda

11 / 15

In the following reaction, identify the salt formed
NH₄OH (aq) + H_{2SO₄ (aq) → _____ + 2H₂O (l)}

NH₄NO₃

(NH₄)₂SO₄

(NH₄)₃PO₄

(NH₄)₂S

12 / 15

Which of the following salt will give acidic solution when dissolved in water?

NH4Cl

NaCl

Na2CO3

CH3COONa

13 / 15

Bleaching powder is used as a disinfectant for water to:

Make water tastier

Remove all the dirt from water

Make water germ-free

Make water clear

14 / 15

Which among the following represents the chemical formula for ‘Plaster of Paris’?

CaSO₄.2H₂O

CaSO₄.1/2H₂O

CaSO₄.H₂O

CaSO₄.10H₂O

15 / 15

Which one of the following salts will dissolve in water to form an alkaline solution?

Potassium carbonate

Sodium chloride

Sodium carbonate

Potassium sulphate

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