7th Grade > Chemistry
ACIDS BASES AND SALTS MCQs
Total Questions : 116
| Page 2 of 12 pages
Answer: Option D. -> Calamine
:
D
Vinegar, orange juice and ant bite are acidic in nature. Calamine is the only basic substance in the given list.
:
D
Vinegar, orange juice and ant bite are acidic in nature. Calamine is the only basic substance in the given list.
Answer: Option B. -> False
:
B
The wastes of many factories contain acids. If they are allowed to flow into the water bodies, the acids will kill fish and other organisms.
The factory wastes are, therefore, neutralised by adding basic substances.
:
B
The wastes of many factories contain acids. If they are allowed to flow into the water bodies, the acids will kill fish and other organisms.
The factory wastes are, therefore, neutralised by adding basic substances.
Answer: Option A. -> Nitric acid
:
A
Fertilizers are added to the soil to improve the yield and growth of the plants. About 80% of the nitric acid is used in the manufacture of fertilizers and a small amount of ammonium nitrate is used to make explosives.
:
A
Fertilizers are added to the soil to improve the yield and growth of the plants. About 80% of the nitric acid is used in the manufacture of fertilizers and a small amount of ammonium nitrate is used to make explosives.
Answer: Option C. -> red
:
C
Methyl orange is orange in colour. It is used in laboratories to determine if a solution is acidic or basic. In acidic medium, it gives red colour and in basic medium, it gives yellow colour.
:
C
Methyl orange is orange in colour. It is used in laboratories to determine if a solution is acidic or basic. In acidic medium, it gives red colour and in basic medium, it gives yellow colour.
Answer: Option D. -> does not changes.
:
D
Turmeric is a yellow coloured natural indicator. Its colour remains the same in an acidic solution and turns red in basic solution. Vinegar is an acid. So the colour of the solution does not changes.
:
D
Turmeric is a yellow coloured natural indicator. Its colour remains the same in an acidic solution and turns red in basic solution. Vinegar is an acid. So the colour of the solution does not changes.
Answer: Option A. -> It turns red.
:
A
Litmus is anacid-base indicator which changes its colour when exposed to an acidic or basic solution. Blue litmus paper turns red in an acidic solution and red litmus paper turns blue in a basic solution. Since vinegar is acidic, it turns blue litmus paper to red.
:
A
Litmus is anacid-base indicator which changes its colour when exposed to an acidic or basic solution. Blue litmus paper turns red in an acidic solution and red litmus paper turns blue in a basic solution. Since vinegar is acidic, it turns blue litmus paper to red.
Answer: Option D. -> No change in any indicator
:
D
Distilled water is neutral and will not result in change in colour of red litmus paper, blue litmus paper andturmeric powder.
:
D
Distilled water is neutral and will not result in change in colour of red litmus paper, blue litmus paper andturmeric powder.
Answer: Option B. -> False
:
B
A natural indicator is a naturally occurring substancewhich changes its colour in acidic or basic media. For example,turmeric, hibiscus, etc are natural indicators.
An artificial indicator is synthesised in a laboratory. Methyl orange is an artificial indicator used in laboratory. It gives red colour in acidic solution and yellow colour in basic solution.
:
B
A natural indicator is a naturally occurring substancewhich changes its colour in acidic or basic media. For example,turmeric, hibiscus, etc are natural indicators.
An artificial indicator is synthesised in a laboratory. Methyl orange is an artificial indicator used in laboratory. It gives red colour in acidic solution and yellow colour in basic solution.
:
Each point: 1 Mark
1)Sodium hydroxide (caustic soda) is used in the manufacture of soap.
2)Ammonium hydroxide is used to remove ink spots from clothes.
3) Calcium hydroxide (slaked lime) is used in the manufacture of bleaching powder.
:
Explanation: 2 Marks
Reaction Diagram: 1 Mark
Changes: 1 Mark
Reason: 1 Mark
The reaction between an acid and a base is known as neutralization. Salt and water are produced in this process with the evolution of heat.
Acid+ Base → Salt + Water + (Heat is evolved)
As for example, when sodium hydroxide (NaOH) is treated with sufficient amount of hydrochloric acid (HCl), a neutralization reaction takes place. Both NaOH and HCl neutralize their effects and form a salt sodium chloride (NaCl) and water (H2O) with the evolution of heat energy.
NaOH + HCl → NaCl + H2O + (Heat is evolved)
Whensulphuric acid is added to lime water, the reaction mixture will become hot because it is a type of neutralizationreaction. An acid is mixed with a base.
So, heat will be evolved in this reaction.
Latest Videos
Latest Test Papers
Login With Google
Old way of Login
Login With Email