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
At high pressure carbon dioxide gas dissolve in water to form
  • A
    Sulphuric acid
  • B
    Citric acid
  • C
    Nitric acid
  • D
    Carbonic acid
    Correct
2
Great care should be taken while using acid or base in laboratory because it may be
  • A
    Corrosive, irritating and harmful to skin
    Correct
  • B
    Combustible and irritating
  • C
    Harmful to skin and lugs
  • D
    Inflammable and volatile
3
Phenolphthalein gives pink colour with base and __________ with acid.
  • A
    Orange
  • B
    Colourless
    Correct
  • C
    Red
  • D
    Blue
4
Antacids are used get relief from acidity in stomach because antacids are
  • A
    Mixture of acid and base
  • B
    Acidic in nature
  • C
    Neutral in nature
  • D
    Basic in nature
    Correct
5
Reaction between acid and base to form salt and water is an example of
  • A
    Substitution reaction
  • B
    Neutralisation reaction
    Correct
  • C
    Endothermic reaction
  • D
    Addition reaction
6
Water soluble bases are called
  • A
    Neutral
  • B
    Basic
  • C
    Aldehydic
  • D
    Alkalise
    Correct
7
When an ant bites, it eject -------------- into stomach.
  • A
    Methonoic acid
  • B
    Formic acid
    Correct
  • C
    Citric acid
  • D
    Lactic acid
8
Excessive use of chemical fertilizers makes the soil
  • A
    Acidic
    Correct
  • B
    Alkaline
  • C
    Saline
  • D
    Basic
9
\({\text{HCl }} + {\text{ NaOH}} \to {\text{NaCl }} + {{\text{H}}_{\text{2}}}{\text{O}}\) is an example of
  • A
    Neutralisation and endothermic reaction
  • B
    Addition and exothermic reaction
  • C
    Addition and endothermic reaction
  • D
    Neutralisation and exothermic reaction
    Correct
10
Organic matter is added to soil to neutralise the excess of base in soil as organic matter
  • A
    Absorbs the acid from the soil
  • B
    Absorbs the base from the soil
  • C
    Release salt on decomposition
  • D
    Release acid on decomposition
    Correct
11
Hydrochloric acid is released in stomach from gastric glands but it do not harm the stomach because
  • A
    Hydrochloric acid is neutralised by base in stomach
  • B
    Hydrochloric acid is a weak acid
  • C
    Hydrochloric acid do not harm the skin
  • D
    Mucus layer prevents the inner wall
    Correct
12
Lactic acid is found in
  • A
    Curd
    Correct
  • B
    Vinegar
  • C
    Orange
  • D
    Apple
13
Distilled water is neutral, it can be verified by using
  • A
    Litmus
  • B
    Methyl orange
  • C
    Universal indictor
    Correct
  • D
    Vanilla
14
____________ solution is applied on the skin when an ant bites.
  • A
    Calamine
    Correct
  • B
    Antiseptic
  • C
    Turmeric
  • D
    Milk of magnesia
15
Which oxide reacts with water to form sulphuric acid?
  • A
    \({\text{S}}{{\text{O}}_{\text{2}}}\)
  • B
    \({\text{S}}{{\text{O}}_{\text{3}}}\)
    Correct
  • C
    CO
  • D
    \({\text{C}}{{\text{O}}_{\text{2}}}\)