Class 7 Acids Bases And Salts CBSE Questions & Answers

Class 7 · Acids Bases And Salts

This is Science Class 7 Acids Bases and Salts CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
The base present in soap is/are
  • A
    Potassium hydroxide and sodium chloride
  • B
    Sodium hydroxide/ potassium hydroxide
    Correct
  • C
    Sodium hydroxide and calcium hydroxide
  • D
    All of these
2
Which of the following is a natural indicator?
  • A
    Oxalic acid.
  • B
    Phenolphthalein
  • C
    Methyl orange
  • D
    Turmeric
    Correct
3
Select the correct pair.
  • A
    Sulphuric acid – salt
  • B
    Magnesium sulphate- Acid
  • C
    Sodium hydroxide – Alkaline
    Correct
  • D
    Sodium chloride- Base
4
In neutralisation reaction
  • A
    Change in colour takes place
  • B
    Heat is always evolve
    Correct
  • C
    Heat is always absorbs
  • D
    Change in odour occurs
5
Reaction between acid and salt produce salt. Acid salt is produced when
  • A
    Weak acid reacts with strong base
  • B
    Weak acid reacts with weak base
  • C
    Strong acid react with strong base
  • D
    Strong acid reacts with weak base
    Correct
6
Which gas is released when acid reacts with metals?
  • A
    Nitrogen
  • B
    Oxygen
  • C
    Hydrogen
    Correct
  • D
    Carbon dioxide
7
Tooth decay is caused due to
  • A
    Decomposition of food particle to produce base
  • B
    Over eating and indigestion
  • C
    Decomposition of food particle to produce acid
    Correct
  • D
    Eating excess of acidic food
8
Blue litmus paper is dipped in a solution. It remains blue. The nature of solution is
  • A
    Either basic or neutral
    Correct
  • B
    Neither acidic nor basic
  • C
    Either basic or acidic
  • D
    Neither basic nor neutral
9
Which of the following is a correct statement?
  • A
    Acids turns blue litmus red
    Correct
  • B
    Base turns blue litmus red
  • C
    Indicators always give colour change with acid
  • D
    Salts are always neutral
10
Sodium chloride turns
  • A
    No change in colour
    Correct
  • B
    Red litmus blue
  • C
    Blue litmus red
  • D
    Methyl orange yellow
11
Field of a farmer has become acidic due to accumulation of water. He should use ____________ to remove acidity from the soil.
  • A
    Any one of these
  • B
    Cow dung and household wastes
  • C
    Lime or chalk
    Correct
  • D
    Manure and fertiliser
12
The acid responsible for inheritance of traits from one generation to other is
  • A
    Deoxyribose acetic acid
  • B
    Ascorbic acid
  • C
    Deoxyribose nucleic acid
    Correct
  • D
    Histamine acid
13
Acid rain is caused by oxide of Sulpher, Nitrogen and Carbon when mixed with rain water to form _____________ respectively.
  • A
    Carbonic acid, sulphuric acid and nitric acid
  • B
    Sulphuric acid, nitric acid and carbonic acid
    Correct
  • C
    Carbonic acid, nitric acid and sulphuric acid
  • D
    Nitric acid, sulphuric acid and carbonic acid
14
Fats in our body contains
  • A
    Amino acid
  • B
    Acetic acid
  • C
    Fatty acid
    Correct
  • D
    Nucleic acid
15
Acids solution are good conductor of electricity as
  • A
    They acids have free electrons
  • B
    Acids contain metal salt
  • C
    Acids have strong bond of attraction
  • D
    Acids produce hydrogen ions (\({{\text{H}}^ + }\)) in water
    Correct