Acids Bases and Salts
Q 1 – Products of a neutralization reaction are always:
a) an acid and a base
b) an acid and a salt
c) a salt and water
d) a salt and a base
Ans. a) an acid and a base
Q 2 – The correct way of making a solution of acid in water is to:
a) add water to acid.
b) add acid to water.
c) mix acid and water simultaneously.
d) add water to acid in a shallow container.
Ans. d) add water to acid in a shallow container.
Acids Bases and Salts Class 7 Science MCQ with answers
Q 3 – An oxide is acidic and has a pungent odour. It could be
(a) sulphur dioxide
(b) carbon dioxide
(c) sodium oxide
(d) nitrogen dioxide
Ans. (d) nitrogen dioxide
Q 4 – What change in colour can be seen when phenolphthalein, a synthetic indicator is added in acidic and basic solutions respectively?
a) red and blue
b) blue and red
c) pink and colourless
d) colourless and pink
Ans. d) colourless and pink
Q 5 – Which of the following is used to extract a natural dye called ‘Litmus’?
a) China rose (Gudhal)
b) Beetroot
c) Lichen
d) Blue berries (Jamun)
Ans. a) China rose (Gudhal)
Q 6 – The correct way of making a solution of acid in water is to
(a) add water to acid
(b) add acid to water
(c) mix acid and water simultaneously
(d) add water to acid in a shallow container
Ans. (b) add acid to water
Acids Bases and Salts Class 7 Science MCQ with answers
Q 7 – Out of these gases which one is used in fire extinguishers
(a) CO2
(b) SO2
(c) NO2
(d) H2S
Ans. (a) CO2
Q 8 – The chemical formula of the milk of magnesia is:
a) CaCO3
b) Mg(OH)2
c) NaHCO3
d) KOH
Ans. b) Mg(OH)2
Q 9 – The common name of sodium hydrogen carbonate used in baking industries is:
a) lime water
b) baking soda
c) caustic potash
d) washing soda
Ans. b) baking soda
Q 10 – The nature of ant’s sting is:
a) neutral
b) Formic acid
c) Weak base
d) Strong base
Ans. b) Formic acid
Q 11 – Products of a neutralisation reaction are always:
(a) an acid and a base
(b) an acid and a salt
(c) a salt and water
(d) a salt and a base
Ans. (c) a salt and water
Q 12 – Turmeric is a natural indicator. On adding its paste to acid and base separately, which colours would be observed.
(a) Yellow in both acid and base
(b) Yellow in acid and red in base
(c) Pink in acid and yellow in base
(d) Red in acid and blue in base
Ans. (b) Yellow in acid and red in base
Q 13 – Phenolphthalein is a synthetic indicator and its colours in acidic and basic solutions, respectively are:
(a) red and blue
(b) blue and red
(c) pink and colourless
(d) colourless and pink
Ans. (d) colourless and pink
Q 14 – When the soil is too basic, plants do not grow well in it. To improve its quality what must be added to the soil?
(a) Organic matter
(b) Quick lime
(c) Slaked lime
(d) Calamine solution
Ans. (a) Organic matter
Q 15 – Which of the following set of substances contain acids?
(a) Grapes, lime water
(b) Vinegar, soap
(c) Curd, milk of magnesia
(d) Curd, vinegar
Ans. (d) Curd, vinegar
Acids Bases and Salts Class 7 Science MCQ with answers
Q 16 – On adding phenolphthalein indicator to a colourless solution, no change is observed. What is the nature of this solution?
(a) Basic
(b) Either acidic or basic
(c) Either acidic or neutral
(d) Either basic or neutral
Ans. (c) Either acidic or neutral
Q 17 – Which of the following is an acid-base indicator?
(a) Vinegar
(b) Lime water
(c) Turmeric
(d) Baking soda
Ans. (c) Turmeric
Q 18 – Acids taste
(a) sour
(b) sweet
(c) bitter
(d) salty
Ans. (a) sour
Q 19 – Bases taste
(a) sweet
(b) sour
(c) bitter
(d) salty
Ans. (c) bitter
Q 20 – Colours of phenolphthalein indicator in acidic and basic medium, respectively are
(a) pink and colourless
(b) colourless and pink
(c) blue and red
(d) red and blue
Ans. (b) colourless and pink
Q 21 – The nature of bases is
(a) acidic
(b) basic
(c) neutral
(d) all of these
Ans. (b) basic
Q 22 – Which of the following feel soapy on touching?
(a) Acid
(b) Base
(c) Salt
(d) None of these
Ans. (b) Base
Q 23 – Which of the following is a natural indicator?
(a) China rose petal
(b) Turmeric
(c) Litmus
(d) All of these
Ans. (d) All of these
Q 24 – The most commonly used natural indicator is
(a) turmeric
(b) beetroot
(c) China rose petal
(d) litmus
Ans. (d) litmus
Q 25 – The correct way of making a solution of acid in water is to
(a) add water to acid
(b) add acid to water
(c) mix acid and water simultaneously
(d) add water to acid in a shallow container
Ans. (b) add acid to water
Q 26 – Which of the following is basic in nature?
(a) Lime water
(b) Baking soda
(c) Both (a) and (b)
(d) Lemon juice
Ans. (c) Both (a) and (b)
Q 27 – Litmus is extracted from
(a) curd
(b) grapes
(c) lichens
(d) cabbage
Ans. (c) lichens
Q 28 – Calcium hydroxide is found in
(a) window cleaner
(b) lime water
(c) soap
(d) lime juice
Ans. (b) lime water
Acids Bases and Salts Class 7 Science MCQ with answers
Q 29 – On adding phenolphthalein indicator to a colourless solution, no change is observed. The nature of the solution may be
(a) acidic or basic
(b) basic
(c) acidic or neutral
(d) basic or neutral
Ans. (c) acidic or neutral
Q 30 – Neutralisation reactioñ is a
(a) physical and reversible change
(b) physical and irreversible change
(c) chemical and reversible change
(d) chemical and irreversible change
Ans. (d) chemical and irreversible change
Q 31 – When a drop of vinegar solution is put on the litmus paper, it turns
(a) red
(b) blue
(c) green
(d) yellow
Ans. (a) red
Q 32 – Tap water is
(a) acidic
(b) basic
(c) neutral
(d) depends on source
Ans. (d) depends on source
Q 33 – When phenolphthalein is added to a acidic solution, it gives
(a) pink colour
(b) red colour
(c) blue colour
(d) no colour
Ans. (d) no colour
Q 34 – A neutralisation reaction gives
(a) salt and water
(b) acid and salt
(c) base and salt
(d) acid and base
Ans. (a) salt and water
Q 35 – Our stomach contains
(a) hydrochloric acid
(b) sodium hydroxide
(c) sulphuric acid
(d) nitric acid
Ans. (a) hydrochloric acid
Q 36 – When we suffer from acidity, we should take
(a) iron tonic
(b) vitamins
(c) antacid
(d) lactocalamine
Ans. (c) antacid
Q 37 – When an ant bites, it injects
(a) acidic liquid
(b) basic liquid
(c) both (a) and (b)
(d) neutral liquids
Ans. (a) acidic liquid
Q 38 – Substances that have sour taste and turn blue litmus red are called
(a) acids
(b) bases
(c) salts
(d) water
Ans. (a) acids
Q 39 – Acid used in eye wash is
(a) carbonic acid
(b) acetic acid
(c) benzoic acid
(d) boric acid
Ans. (d) boric acid
Acids Bases and Salts Class 7 Science MCQ with answers
Q 40 – Acid which is used as a source of vitamin C is
(a) citric acid
(b) carbonic acid
(c) boric acid
(d) tartaric acid
Ans. (a) citric acid
Q 41 – A base which is used for removing grease and stains from woollen clothes is
(a) ammonium hydroxide
(b) magnesium hydroxide
(c) sodium hydroxide
(d) calcium hydroxide
Ans. (a) ammonium hydroxide
Q 42 – Neutralisation is a reaction between
(a) two acids
(b) two bases
(c) one acid and one base
(d) one acid and one neutral substance’
Ans. (c) one acid and one base
Q 43 – Sting of an ant contains
(a) vinegar
(b) common salt
(c) formic acid
(d) milk of magnesia
Ans. (c) formic acid
Q 44 – Lime water turns
(a) red litmus into blue
(b) blue litmus to red
(c) no change
(d) can’t predict
Ans. (a) red litmus into blue
Q 45 – Common salt is
(a) acidic
(b) basic
(c) neutral
(d) none of these
Ans. (c) neutral
Q 46 – Milk of magnesia is used as antacid because
(a) it is acidic
(b) it is basic
(c) it is neutral
(d) all of above
Ans. (b) it is basic
Q 47 – Colour of phenolphthalein in acidic solution is
(a) colourless
(b) pink
(c) yellow
(d) orange
Ans. (a) colourless
Q 48 – Process in which acids and bases react to form salt and water is called
(a) neutralisation
(b) hydrogenation
(c) sublimation
(d) all of these
Ans. (a) neutralization