CBSE Class 10 Science Acids Bases and Salts MCQs Set 06

Question. Calcium carbonate is the chemical formula of
(a) limestone
(b) chalk
(c) marble
(d) all (a), (b) and (c)

Answer: D

Question. On adding dilute HCl to copper oxide in a beaker, the solution turns blue-green due to formation of
(a) copper(II) hydroxide
(b) copper nitrate
(c) copper (II) chloride
(d) copper sulphate

Answer: C

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. In an attempt to demonstrate electrical conductivity through an electrolyte, the alongside apparatus was set up. Which among the following statement(s) is(are) correct? (Diagram)
(i) Bulb will not glow because electrolyte is not acidic
(ii) Bulb will glow because NaOH is a strong base 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. A solution turns red litmus blue, its pH is likely to be:
(a) 1
(b) 4
(c) 5
(d) 10. 

Answer: D

Question. A solution ‘X’ reacts with crushed egg shells to give a gas which turns lime water milky. The solution contains:
(a) NaCl
(b) HCl
(c) LiCl
(d) KCl.

Answer: B

Question. A student learns that when sodium chloride reacts with water, it forms sodium hydroxide.
Which type of reaction results in the formation of sodium hydroxide?
(a) Neutralization reaction
(b) Displacement reaction
(c) Combination reaction
(d) Decomposition reaction

Answer: D

Question. Which of the following is the best possible application of calcium oxychloride?
(a) To make the water soft
(b) To reduce the pH of water
(c) To disinfect the water
(d) To change the state of water

Answer: C

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. Sodium carbonate is a basic salt because it is a salt of
(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. The chemical formula for plaster of Paris is:
(a) CaSO₄.2H₂O
(b) CaSO₄.H₂O
(c) CaSO . 1/2 H₂O
(d) 2CaSO₄.H₂O

Answer: C

Question. A visually challenged student, has to perform a lab test to detect the presence of acid in a given solution. The acid-base indicator preferred by him will be:
(a) Blue litmus
(b) Clove oil
(c) Red cabbage extract
(d) Hibiscus extract

Answer: B

Question. The chemical reaction shows the reactants for the formation of baking soda.
NaCl + H₂O + CO₂ + NH₃ → X + Y
What are X and Y?
(a) X: NH₃Cl; Y: NaHCO₃
(b) X: NH₄Cl; Y: NaHCO₃
(c) X: HCl; Y: NaHCO₃
(d) X: NH₄Cl; Y: NaHCO₂

Answer: B

Question. Incorrect statement about acids is/are
(a) they have sour taste
(b) they may change the colour of indicator
(c) they change the colour of blue litmus to red
(d) they change the colour of red litmus to blue

Answer: D

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

Answer: A

Question. Which is a soluble base in water?
(a) Cu(OH)₂
(b) Fe(OH)₃
(c) Zn(OH)₂
(d) KOH

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. Which of the following statements is correct about an aqueous solution of an acid and or a nbase?
(i) Higher the pH, stronger the acid (ii) Higher the pH, weaker the acid
(iii) 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. Which of the following solutions will turn phenolphthalein pink?
(a) HCl(aq)
(b) CO₂(aq)
(c) KOH(aq)
(d) H₂SO₄(aq)

Answer: C

Question. Identify the correct representation of reaction occurring during chlor-alkali process.
(a) 2NaCl(l) + 2H₂O(l) 2NaOH(l) + Cl₂(g) + H₂(g)
(b) 2NaCl(aq) + 2H₂O(aq) 2NaOH(aq) + Cl₂(g) + H₂(g)
(c) 2NaCl(aq) + 2H₂O(l) 2NaOH(aq) + Cl₂(aq) + H₂(aq)
(d) 2NaCl (aq) + 2H₂O (l) 2NaOH (aq) + Cl₂(g) + H₂(g)

Answer: D

Question. The equation shows the reaction of hydrochloric acid with sodium hydroxide.
HCl+ NaOH → NaCl + H₂O
If the pH of the salt is 7, what are the positive and negative radicals in the salt?
(a) Na - negative radical; Cl - negative radical
(b) Na - positive radical; Cl - negative radical
(c) Na - positive radical; Cl - positive radical
(d) Na - negative radical; Cl - positive radical

Answer: B

Question. Which of the following properties is closely related to acids?
(a) Contain the hydroxide ion
(b) Bitter taste
(c) Salty taste
(d) Sour taste

Answer: D

Question. The pH of a solution is 5.0. Its hydrogen ion concentration is decreased by 100 times, the solution will be:
(a) more acidic
(b) basic
(c) neutral
(d) unaffected

Answer: C

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

Answer: C

Question. Washing soda is obtained from the recrystallization of sodium carbonate. How is sodium carbonate obtained from baking soda?
(a) By heating the baking soda
(b) By reacting the baking soda with base
(c) By reacting the baking soda with acid
(d) By adding water to baking soda

Answer: A

Question. When water of crystallization is removed from copper sulphate solution, how does the colour of the salt change?
(a) From white to blue
(b) From white to red
(c) From blue to red
(d) From blue to white

Answer: D

Question. Which of the following statements is true for acids?
(a) Bitter and change red litmus to blue
(b) Sour and change red litmus to blue
(c) Sour and change blue litmus to red
(d) Bitter and change blue litmus to red

Answer: C

Question. CuO + (X) → CuSO₄ + H₂O. Here (X) is
(a) CuSO₄
(b) HCl
(c) H₂SO₄
(d) HNO₃

Answer: C

Question. Tomato is a natural source of which acid?
(a) Acetic acid
(b) Citric acid
(c) Tartaric acid
(d) Oxalic acid

Answer: D

Question. Which solution will change blue litmus to red?
(a) NaOH(aq)
(b) H₂SO₄(aq)
(c) KCl(aq)
(d) NH4OH(aq)

Answer: B

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

Answer: A

Question. A student learns that plants grow best when the pH of the soil is slightly acidic. Which range of pH is most suited for plant growth? 
(a) 11 – 14
(b) 5.5 – 7
(c) 1 – 3
(d) 7 – 9

Answer: B

Assertion and Reason
(a) Both ‘A’ and ‘R’ are true and ‘R’ is correct explanation of the assertion.
(b) Both ‘A’ and ‘R’ are true but ‘R’ is not correct explanation of the assertion.
(c) ‘A’ is true but ‘R’ is false.
(d) ‘A’ is false but ‘R’ is true.

Question. Assertion: pH of HCl solution in our stomach is about 2.
Reason: HCl in our stomach helps in digestion.

Answer: B

Question. Assertion: If the pH inside the mouth decreases below 5.5, the decay of tooth enamel begins.
Reason: The bacteria present in mouth degrades the sugar and left over food particles and produce acids that remains in the mouth after eating.

Answer: A

Question. Assertion: pH = 7 signifies pure water.
Reason: At this pH, [H+] = [OH–] = 10^–7.

Answer: D

Question. Assertion: pH = 11 is strongly basic, pH=7 is neutral.
Reason: pH = 5 is weak acid and pH= 2 is strong acid.

Answer: B

Question. Assertion: Higher the pH, less will be H₃O+ concentration in the solution.
Reason: pH of blood is 9.36 to 9.42.

Answer: C