CBSE Class 10 Science Acids Bases and Salts MCQs Set 04

Question: Which of the following natural sources contains oxalic acid?
a) lemon
b) orange
c) tomato
d) tamarind
Answer: c

Question: Which of the following is incorrectly matched ?
a) Tomato – tartaric acid
b) Ant sting – citric acid
c) Citrus fruit – citric acid
d) Curd – lactic acid
Answer: b

Question: Which of the following is not basic in nature ? 
a) KOH
b) ZnO
c) Al(OH)₃
d) NaCl
Answer: a

Question: Which of the following is a strong acid ?
a) Lactic acid
b) Ascorbic acid
c) Sulphuric acid
d) Formic acid
Answer: c

Question: Plaster of Paris (CaSO4 . 1/2HO) on mixing with water sets to form
a) CaSO₄.H₂O
b) (CaSO₄ . 1x1/2HO)
c) CaSO₄.2H₂O
d) CaSO₄ . 2x1/2HO
Answer: c

Question: Plaster of Paris hardens by
a) giving off CO₂
b) changing into CaCO₃
c) combining with water
d) giving out water
Answer: c

Question: If an unknown solution turns blue litmus red, then the pH of the solution is more likely to be
a) 12
b) 10
c) 7
d) 4
Answer: d

Question: What is the pH of a 0.00001 molar HCl solution?
a) 1
b) 9
c) 5
d) 4
Answer: c

Question: To prevent tooth decay we are advised to brush our teeth regularly. The nature of the tooth paste commonly used is
a) acidic
b) neutral
c) basic
d) corrosive
Answer: c

Question: The acid found in an ant sting is
a) acetic acid
b) citric acid
c) tartaric acid
d) Methanoic acid
Answer: d

Question: Which of the following is a dibasic acid ?
a) HCla
b) H₃PO₄
c) HNO₃
d) H₂SO₄
Answer: d

Question: When dilute hydrochloric acid is added to granulated zinc placed in a test tube, the observation made is that
a) the surface of the metal turns shining
b) the reaction mixture turns milky
c) odour of chlorine is observed
d) a colourless and odourless gas is evolved with bubbles 18. The reaction of metal with acid results in the formation of 
Answer: d

Question: Phenolphthalein is
a) yellow in acidic medium, pink in basic medium
b) pink in acidic medium, colourless in basic medium
c) colourless in acidic medium, pink in basic medium
d) pink in acidic medium, yellow in basic medium
Answer: c

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 options
Answer: b

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: b

Question: Which gas is evolved when acids react with metal carbonates ?
a) CO₂
b) H₂
c) NH₃
d) O₂
Answer: a

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: When sodium chloride reacts with sulphuric acid, a gas is evolved which gives dense white fumes with ammonia) Which gas is evolved?
a) HCl
b) NH4Cl
c) NH4OH
d) (NH₄)₂SO₄
Answer: a

Question: For dilution of concentrated acid we should add 
a) water into concentrated acid
b) concentrated acid into water
c) first water into acid and then more acid
d) Both water into concentrated acid and concentrated acid into water
Answer: b

Question: Soda-acid fire extinguisher extinguishes the fire by
a) cutting the supply of air
b) removing the combustible substance
c) raising the ignition temperature
d) None of these
Answer: a

Question: Plaster of Paris is obtained
a) by adding water to calcium sulphate
b) by adding sulphuric acid to calcium hydroxide
c) by heating gypsum to a very high temperature
d) by cooling gypsum
Answer: c

Question: Water soluble bases are known as?
a) Neutral
b) Base
c) Acid
d) Alkali
Answer: d

Question: Identify the basic salt from the following salts:
a) Na₂CO₃
d) NH₄Cl
c) NaNO₃
d) KCl
Answer: a

Question: Which of the following substances will not give carbon dioxide on treatment with dilute acid?
a) Marble
b) Limestone
c) Baking soda
d) Lime
Answer: d

Question: Which one of the following statements is correct about universal indicator?
a) It is a mixture of HCl and NaOH
b) It is a mixture of many indicators
c) It is a solution of phenolphthalein in alcohol
d) It is a solution of phenolphthalein in water.
Answer: b

Question: The pH of a sample of pure water is 7 at room temperature. What is its pH when a pinch of solid sodium bicarbonate is dissolved in it?
a) vary near to 7
b) less than 7
c) more than 7
d) exactly 7
Answer: c

Question: Equal volumes of hydrochloric acid and sodium hydroxide solutions of same concentration are mixed and the pH of the resulting solution is checked with a pH paper. What would be the colour obtained? (You may use colour guide in the figure given below).
a) Red
b) Yellow
c) Yellowish green
d) Blue
Answer: c

Question: Two solution A and B were found to have pH value of 6 and 8 respectively. The inference which can be drawn is that
a) the acid strength of the solution B is higher than that of A
b) A is an acid while B is a base
c) Both are acidic solutions
d) Both are basic solutions
Answer: b

Question: Which of the following statements is true regarding acids and bases ? 
a) Acid and bases don't react with each other
b) Acids mixed with bases neutralise each other
c) Acids mixed with bases make stronger acids
d) Acids mixed with bases make stronger bases
Answer: b

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: Which one is suitable method to find the accurate pH value?
a) pH meter
b) pH paper
c) Universal indicator
d) Litmus solution
Answer: c

Question: Which of the following substances will not give carbon dioxide on treatment with dilute acid?
a) Marble
b) Limestone
c) Baking soda
d) Lime
Answer: d

Question: Calcium phosphate is present in tooth enamel. Its nature is:
a) Basic
b) Acidic
c) Neutral
d) Amphoteric
Answer: a