1 ) Which of the following is a chemical change ?
A ) Boiling of water
B ) Bursting of an inflated balloon
C ) Souring of milk
D ) Dissolution of salt in water.
Ans C ) Souring of milk
2 ) Which of the following is an example of an ionic compound?
A ) H2
B ) O2
C ) H2O
D ) NaCl
Ans D ) NaCl
3 ) Two atoms of same element always form
A ) Ionic bond
B ) Covalent bond
C ) Strong bond
D ) Electrovalent bond
Ans B ) Covalent bond
4 ) Which of the following substances is used in the cold drink called ‘soda lemon’ ?
A ) Baking soda B ) Washing soda C ) Lime water
D ) Lime stone
Ans A ) Baking soda
5 ) Baking soda with lemon juice releases which gas?
A ) O2 B ) CO2 C ) H2
D ) HCl
Ans B ) CO2
6 ) Hard water contains the chloride and sulphate salts of …………… and in dissolved state.
A ) Calcium and magnesium
B ) Calcium and sodium
C ) Sodium and magnesium
D ) Sulfur and magnesium
Ans A ) Calcium and magnesium
7 ) Shahabad tile is cleaned with concentrated hydrochloric acid.
A ) True
B ) False
Ans B ) False
8 ) Citric acid with sodium bicarbonate give which salt?
A ) Sodium chloride
B ) Citric oxide
C ) Sodium citrate
D ) Citric carbonate
Ans C ) Sodium citrate
9 ) Wood, coal, petrol or cooking gas are burnt for getting …………….
A ) Fuel
B ) Nitrogen
C ) Energy
D ) Electricity
Ans C ) Energy
10 ) Find the odd one out.
A ) NaCl B ) H2O C ) MgCl2 D ) KCl
Ans B ) H2O
11 ) New substances formed as a result of the reaction are called …………….
A ) Reactants
B ) Original substances
C ) Producers
D ) Products
Ans D ) Products
12 ) Which of the following is a manmade chemical change ?
A ) Respiration
B ) Photosynthesis
C ) Foul smell from a spoiled food
D ) Softening of water.
Ans D ) Softening of water.
13 ) Chemical name of baking soda is …………… .
A ) Sodium chloride
B ) Sodium carbonate
C ) Calcium hydroxide
D ) Sodium bicrbonate
Ans D ) Sodium bicrbonate
14 ) Freshly prepared solution of calcium hydroxide in water is called …………… .
A ) Baking soda B ) Soda water C ) Lime water D ) Lime stone
Ans C ) Lime water
15 ) Which of the following substances react with oxygen in respiration?
A ) Glucose
B ) Carbon dioxide
C ) Water
D ) Carbon
Ans A ) Glucose
16 ) Which of the following is an ionic compound ?
A ) H2 B ) H2O C ) KF
D ) HCl
Ans C ) KF
17 ) The chemical bond formed by sharing of valence electrons of two atoms with each other is called a ……………
bond.
A ) Ionic
B ) Anionic
C ) Electrovalent
D ) Covalent
Ans D ) Covalent
18 ) Respiration increases the amount of gas in the body.
A ) O2 B ) CO2 C ) H2
D ) HCl
Ans B ) CO2
19 ) During respiration, in the body is used up to produce energy.
A ) Water
B ) Glucose C ) Starch D ) Carbon
Ans B ) Glucose
20 ) During any …………… change, composition of original substance changes to form new substance with a different composition and properties.
A ) Chemical B ) Natural C ) Physical
D ) Mechanical
Ans A ) Chemical
21 ) Acid and alkali reaction is known as ……………
A ) Decomposition
B ) Oxidation
C ) Neutralization
D ) Dissociation
Ans C ) Neutralization
22 ) What happens when carbon dioxide reacts with freshly prepared lime water ?
A ) The lime water turns milky.
B ) The solution remains colourless.
C ) Oxygen gas is released.
D ) The chemical composition of the lime water does not change.
Ans A ) The lime water turns milky.
23 ) The compound formed by means of one or more ionic bonds is called …………….
A ) Ionic compound
B ) Covalent compound C ) Valence compound D ) Anion
Ans A ) Ionic compound
24 ) An ion forms the same number of ionic bonds as its ……………
A ) Electrons
B ) Configuration
C ) Valency
D ) Size
Ans C ) Valency
25 ) The common substance that burns in all the fuels is ‘… ‘.
A ) Carbon
B ) Hydrogen C ) Oxygen D ) Chlorine
Ans A ) Carbon
26 ) The electronic configuration of sodium is …………… .
A ) (2, 8, 8, 1)
B ) (2, 8, 1)
C ) (2, 8, 8, 2)
D ) (2, 8, 2)
Ans B ) (2, 8, 1)
27 ) Respiration is a continuously occurring biological process.
A ) True
B ) False
Ans A ) True
28 ) Which of the following is NOT a chemical change ?
A ) Digestion of food
B ) Formation of water vapour from liquid water.
C ) Baking of a cake
D ) Changing colour of fallen leaves
Ans B ) Formation of water vapour from liquid water.
29 ) In MgCl2, charge on Cl is ……………
A ) -1
B ) +1
C ) -2
D ) +2
Ans A ) -1
30 ) There are electrons in the valence shell of oxygen atom.
A ) Six
B ) Five
C ) Two
D ) One
Ans A ) Six
31 ) When carbon dioxide gas reacts with freshly prepared lime water, the products formed are …………… .
A ) Calcium carbonate and oxygen B ) Calcium hydroxide and water C ) Calcium carbonate and water D ) Calcium hydroxide and oxygen
Ans C ) Calcium carbonate and water
32 ) Which of the following characteristics help to identify a chemical change when a pinch of baking soda is added to the lemon juice ?
A ) Colour and taste change
B ) Taste change and release of gas C ) Colour change and release of gas D ) Only colour change
Ans B ) Taste change and release of gas
