CBSE Class 10 Science Acids Bases and Salts MCQs

MCQ Questions for NCERT Class 10 Science Acids Bases and Salts

Question : What happens when a base is added to vanilla?
(a) Color of vanilla changes into red
(b) Vanilla becomes colorless
(c) Vanilla loses its smell
(d) Nothing happens

Answer  :  C

Question :  Calcium phosphate is present in tooth enamel. Its nature is
(a) basic
(b) acidic
(c) neutral
(d) amphoteric

Answer  :  A

Question : The odour of acetic acid resembles that of
(a) Rose
(b) Burning Plastic
(c) Vinegar
(d) Kerosene

Answer  :  C

Question : Ammonium sulphate salt is
(a) Basic salt
(b) Acidic salt
(c) Neutral salt
(d) Complex salt

Answer  :  A

Question : An indicator is one kind of the following compound
(a) Strong acid only
(b) Reducing agent
(c) Weak base or acid only
(d) Complex salt

Answer  :  C

Question : Chemical formula of baking soda is:
(a) MgSO4
(b) Na2CO3
(c) NaHCO3
(d) MgCO3

Answer  :  C

Question : An aqueous solution turns red litmus solution blue. Excess addition of which of the following solution would reverse the change?
(a) Baking powder
(b) Lime
(c) Ammonium hydroxide solution
(d) Hydrochloric acid

Answer  : D

Question : What is the pH value of sodium chloride?
(a) 7
(b) More than 7
(c) Less than 7
(d) Zero

Answer  : A

Question : Dilute acid does not produce carbon dioxide on being treated with:
(a) Marble
(b) Lime
(c) Baking soda
(d) Limestone

Answer  : B

Question : Setting of Plaster of Paris takes place due to
(a) Oxidation
(b) Reduction
(c) Dehydration
(d) Hydration

Answer  : D

Question : Sodium carbonate is a basic salt because it is a salt of a
(a) strong acid and strong base
(b) weak acid and weak base
(c) strong acid and weak base
(d) weak acid and strong base

Answer  : D

Question : Lime water is
(a) CaO
(b) Ca(OH)₂
(c) CaCO₃
(d) CaCI₂

Answer  : B

Question : Which one of the following types of medicines is used for treating indigestion?
(a) Antibiotics
(b) Analgesic
(c) Antacid
(d) Antiseptic

Answer  :  C

Question. You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. Which of them will turn red litmus to blue.
(a) Acid
(b) Base
(c) Water
(d) All of the above

Answer : B

Question. Acids react with metals to liberate _________gas
(a) Carbon dioxide
(b) Carbon monoxide
(c) Hydrogen
(d) Water

Answer : C

Question. Acids react with metal carbonates to liberate ______ gas
(a) Carbon dioxide
(b) Carbon monoxide
(c) Hydrogen
(d) Water

Answer : A

Question. Lime water turns milky when carbon dioxide is passed due to the formation of ______.
(a) CaCO₃
(b) CaO
(c) CO₂
(d) CaSO₄

Answer : A

Question. The milkiness (on passing excess carbondioxide gas through lime water) disappears due to the formation of:
(a) Calcium carbonate CaCO₃
(b) Calcium hydrogen carbonate CaHCO₃
(c) Calcium oxide CaO
(d) Calcium Nitrate Ca(NO₃)₂

Answer : B

Question. Acids react with bases to form salt and water. This reaction is known as:
(a) Combination
(b) Decomposition
(c) Neutralisation
(d) reduction

Answer : C

Question. A calcium compound reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle. Identify the compound and the gas evolved)
(a) Calcium Carbonate, Carbon dioxide
(b) Calcium chloride, carbondioxide
(c) Calcium oxide, hydrogen
(d) Calcium carbonate, hydrogen

Answer : A

Question. How is the concentration of hydronium ions (H₃O⁺) affected when a solution of an acid is diluted?
(a) Increases
(b) Decreases
(c) Remains the same
(d) Becomes zero

Answer : A

Question. Why does dry HCl gas not change the colour of the dry litmus paper?
(a) Blue litmus becomes dry in presence of dry HCl gas
(b) No H₃O⁺ ions will be present, litmus changes colour only in the presence of H₃O⁺ ions
(c) HCl gas acts asa dehydrating agent
(d) None of the above

Answer : B

Question. When a bee stings, immediately a paste of lime is put on the sting. Why?
(a) Bee sting is made of a base
(b) Bee sting contains an acid called formic acid) It gets neutralised with CaO
(c) Bee sting is acidic due to hydrochloric acid and this is neutralised
(d) All of the above.

Answer : B

Question : Methyl orange is
(a) Pink in acidic medium, yellow in basic medium
(b) Yellow in acidic medium, pink in basic medium
(c) Colourless in acidic medium, pink in basic medium
(d) Pink in acidic medium, colourless in basic medium.

Answer  :  A

Question : Tooth enamel is made up of
(a) calcium phosphate
(b) calcium carbonate
(c) calcium oxide
(d) potassium

Answer  :  A

Question : If pH of solution is 13, it means that if is
(a) Weakly acidic
(b) Weakly basic
(c) Strongly acidic
(d) Strongly Basic

Answer  : D

Question : When hydrogen chloride gas is prepared on a humid day, the gas is usually passed through the guard tube containing calcium chloride. The role of calcium chloride taken in the guard tube is to
(a) absorb the evolved gas
(b) moisten the gas
(c) absorb moisture from the gas
(d) absorb Cl– ions from the evolved gas

Answer  :  C

Question : An aqueous solution with pH-zero is
(a) Acidic
(b) Alkaline
(c) Neutral
(d) Amphoteric

Answer  :  A

Question : The Ph of a solution of HCL is 4. This shows that the molarity of the solution is
(a) 4.0M
(b) 0.4M
(c) 0.0001M
(d) 0.001M

Answer  :  A

Question : An aqueous solution with pH-zero is
(a) Acidic
(b) Alkaline
(c) Neutral
(d) Amphoteric

Answer  :  A

Question : Which of the following acid is also known as vinegar?
(a) Dilute hydrochloric acid
(b) Dilute sulphuric acid
(c) Dilute acetic acid
(d) Dilute tartaric acid

Answer  :  C

Question : A solution reacts with crushed egg-shells to give a gas that turns lime-water milkey. The solution contains
(a) NaCl
(b) HCl
(c) LiCl
(d) KCl

Answer  :  B

Question : Bleaching powder is used as a disinfectant for water to:
(a) Make water tastier
(b) Remove all the dirt from water
(c) Make water germ-free
(d) Make water clear

Answer  :  C

Question : Which of the following salts does not contain water of crystallisation? [NCERT Exemplar Problems]
(a) Blue vitriol
(b) Baking soda
(c) Washing soda
(d) Gypsum

Answer  :  B

Question. Sodium carbonate is a basic salt because it is a salt of [NCERT Exemplar Problems]
(a) strong acid and strong base.
(b) weak acid and weak base.
(c) strong acid and weak base.
(d) weak acid and strong base.

Answer : D

Question. When hydrogen chloride gas is prepared on a humid day, the gas is usually passed through the guard tube containing calcium chloride. The role of calcium chloride taken in the guard tube is to
(a) absorb the evolved gas
(b) moisten the gas
(c) absorb moisture from the gas
(d) absorb Cl– ions from the evolved gas

Answer : C

Question. Which one of the following salts does not con-tain water of crystallisation?
(a) Blue vitriol
(b) Baking soda
(c) Washing soda
(d) Gypsum

Answer : B

Question. In terms of acidic strength, which one of the following is in the correct increasing order?
(a) Water < Acetic acid < Hydrochloric acid
(b) Water < Hydrochloric acid < Acetic acid
(c) Acetic acid < Water < Hydrochloric acid
(d) Hydrochloric acid < Water < Acetic acid

Answer : A

Question. Brine is an
(a) aqueous solution of sodium hydroxide
(b) aqueous solution of sodium carbonate
(c) aqueous solution of sodium chloride
(d) aqueous solution of sodium bicarbonate

Answer : C

Question. Na₂CO₃ . 10H₂O is
(a) washing soda
(b) baking soda
(c) bleaching powder
(d) tartaric acid

Answer : A

Question. Sodium carbonate is a basic salt because it is a salt of a
(a) strong acid and strong base
(b) weak acid and weak base
(c) strong acid and weak base
(d) weak acid and strong base

Answer : D

Question. Alkalis are
(a) acids, which are soluble in water
(b) acids, which are insoluble in water
(c) bases, which are insoluble in water
(d) bases, which are soluble in water

Answer : D

Question. Egg shell is made up of
(a) CaCO₃
(b) CaO
(c) Ca(OH)₂
(d) CaCl₂

Answer : A

Question. Curd cannot be stored in
(i) Brass vessel
(ii) Copper vessel
(iii) Steel
(iv) Bronze
(a) (i), (ii), (iii)
(b) (ii), (iii), (iv)
(c) (i), (ii), (iv)
(d) (i), (iii), (iv)

Answer : C

Question. The apparatus given in the adjoining figure was set up to demonstrate electrical conductivity.
Which of the following statement(s) is (are) correct?
(i) Bulb will not glow because electrolyte is not acidic.
(ii) Bulb will glow because HCl is a strong acid and furnishes ions for conduction.
(iii) Bulb will not glow because circuit is incomplete.
(iv) Bulb will not glow because it depends upon the type of electrolytic solution.
(a) (i) and (iii)
(b) (ii) and (iv)
(c) (ii) only
(d) (iv) only

Answer : C

Question. Calcium phosphate is present in tooth enamel. Its nature is [NCERT Exemplar Problems]
(a) basic
(b) acidic
(c) neutral
(d) amphoteric

Answer : A 

Question. What happens when a solution of an acid is mixed with a solution of a base in a test tube?
(i) Temperature of the solution decreases
(ii) Temperature of the solution increases
(in) Temperature of the solution remains the same
(iv) Salt formation takes place
(a) (i) and (iv)
(b) (i) and (iii)
(c) (ii) only
(d) (ii) and (iv)

Answer : D

Question. Lime water reacts with chlorine to give
(a) bleaching powder
(b) baking powder
(c) baking soda
(d) washing soda

Answer : C

Question. Rain is called acid rain when its:
(a) pH falls below 7
(b) pH falls below 6
(c) pH falls below 5.6
(d) pH is above 7

Answer : C

Question. CaOCl₂ will liberate Cl₂ gas in presence of
(i) CO₂
(ii) HCl
(iii) CO
(iv) NO
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)

Answer : A

Question. What happens when a solution of an acid is mixed with a solution of a base in a test tube? [NCERT Exemplar Problems]
(i) The temperature of the solution increases
(ii) The temperature of the solution decreases
(iii) The temperature of the solution remains the same
(iv) Salt formation takes place.
(a) (i) only
(b) (i) and (iii)
(c) (ii) and (iii)
(d) (i) and (iv)

Answer : D

Question. Sodium hydroxide is a
(a) weak base
(b) weak acid
(c) strong base
(d) strong acid

Answer : C

Question. An aqueous solution turns red litmus solution blue. Excess addition of which of the following solution would reverse the change?
(a) Baking powder
(b) Lime
(c) Ammonium hydroxide solution
(d) Hydrochloric acid

Answer : D

Question. Which of the following statements is correct about an aqueous solution of an acid and of a base?
(i) Higher the pH, stronger the acid
(ii) Higher the pH, weaker the acid
(in) Lower the pH, stronger the base
(iv) Lower the pH, weaker the base
(a) (i) and (iii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)

Answer : D

Question. When copper oxide and dilute hydrochloric acid react, colour changes to
(a) white
(b) bluish-green
(c) blue-black
(d) black

Answer : B

Question. Nettle sting is a natural source of which acid?
(a) MetiWanoic acid
(b) Lactic acid
(c) Citric acid
(d) Tartaric acid

Answer : A

Question. A sample of soil is mixed with water and allowed to settle. The clear supernatant solution turns the pH paper yellowish-orange. Which of the following would change the colour of this pH paper to greenish-blue? 
(a) Lemon juice
(b) Vinegar
(c) Common salt
(d) An antacid

Answer : D

Question. Sodium hydroxide turns phenolphthalein solution
(a) pink
(b) yellow
(c) colourless
(d) orange

Answer : A

Question. Chemical formula of washing soda is
(a) Na₂C0₃ . 7H₂O
(b) Na₂C0₃ . 5H₂O
(c) Na₂C0₃ . 2H₂O
(d) Na₂C0₃ . 10H₂O

Answer : D

Question. Tooth enamel is made up of
(a) calcium phosphate
(b) calcium carbonate
(c) calcium oxide
(d) potassium

Answer : A

Question. Which of the following is not a acidic salt?
(a) CuSO₄
(b) NH₄Cl
(c) FeCl₃
(d) CH₃COONa

Answer : D

Question. A solution of NaCl
(i) will turn red litmus blue
(ii) will turn pH paper green
(iii) will turn blue litmus red
(iv) will not affect litmus
(a) (i) and (ii)
(b) (i), and, (iii)
(c) (i) and (iv)
(d) (ii) and (iv)

Answer : D

Question. Many salts absorbs water from atmosphere. This property is called
(a) deliquescence
(b) efflorescence
(c) hydration
(d) addition

Answer : A

Question. What is formed when zinc reacts with sodium hydroxide?
(a) Zinc hydroxide and sodium
(b) Sodium zincate and hydrogen gas
(c) Sodium zinc-oxide and hydrogen gas
(d) Sodium zincate and water

Answer : B

Question. Which of the following gives the correct increasing order of acidic strength ?
(a) Water < Acetic acid < Hydrochloric acid
(b) Water < Hydrochloric acid < Acetic acid
(c) Acetic acid < Water < Hydrochloric acid
(d) Hydrochloric acid < Water < Acetic acid

Answer : A

Question : A sample of soil is mixed with water and allowed to settle. The clear supernatant solution turns the pH paper yellowish-orange. Which of the following would change the colour of this pH paper to greenish-blue?
(a) Lemon juice
(b) Vinegar
(c) Common salt
(d) An antacid

Answer  :  D

Question : Some fruits like mango, lemon, raw grapes, orange, et(c) , have a sour taste due to the presence of:
(a) Acetic acid
(b) Citric acid
(c) Lactic acid
(d) Oxalic acid

Answer  :  B

Question : The H + ion concentration of a solution is 1.0×10-5m. The solution is
(a) Acidic
(b) Alkaline
(c) Neutral
(d) Amphoteric

Answer  :  A

Question : Which one of the given is incorrect?
(a) Acids turns blue litmus paper red
(b) Aqueous solutions of acids conduct electricity
(c) Acids react with certain metals to form hydrogen gas
(d) None of these

Answer  :  D

Question : Acid present in apple is :
(a) Oxalic acid
(b) Malic acid
(c) Acetic acid
(d) Formic acid

Answer  :  B

Question : A strong acid:
(a) Completely gets ionized in water
(b) Partially gets ionized in water
(c) Do not get ionized in water
(d) All the these

Answer  :  A

Question : Which one of the given is true, if a substance has a pH value of 4?
(a) The substance is a base
(b) The substance is an acid
(c) The substance is a neutral substance
(d) Either (1) or (2)

Answer  :  B

Question : Which of the following phenomena occurs when acid is mixed with water
(a) Neutralization
(b) Dilution
(c) Ionization
(a) Only (b) is correct
(b) (a) & (b) are correct
(c) (b) & (c) are correct
(d) Only (c) is correct

Answer  :  C

Question : Due to excess passing of CO2 through an aqueous solution of slaked lime, its milkiness fades because
(a) Calcium carbonate is produced
(b) Calcium bi-carbonate is produced
(c) Calcium oxide is produced
(d) Due to the production of more heat

Answer  :  A

Question : During the preparation of HCl gas on a humid day, the gas is usually passed through the guard tube containing CaCl₂. The purpose of using CaCl₂ is
(a) To add moisture to the gas (HCl)
(b) To absorb HCl gas
(c) To absorb moisture from HCl gas
(d) To Use it as a catalyst

Answer  :  C

Question : Black ash is
(a) Dry KOH
(b) Barium sulphide
(c) Charcoal
(d) Hydrated KOH

Answer  :  B

Question : Phenolphthalein’s colour in basic medium is ____but in acid it is ______.
(a) Pink, Colorless
(b) Yellow, Pink
(c) Pink, Orange
(d) Blue, Red

Answer  :  A

Question : A drop of liquid sample was put on the pH paper, paper turned blue. The liquid sample must be of
(a) Lemon Juice
(b) HCl
(c) Sodium bicarbonate
(d) Ethanoic aci(d)

Answer  :  C

Question : When a bee stings, immediately a paste of lime is put on the sting. Why?
a) Bee sting contains an acid called formic aci It gets neutralised with CaO .
b) Bee sting is made of a base
c) Bee sting is acidic due to hydrochloric acid and this is neutralised
d) All of the above.
Answer : A