Class 7 Science Chapter 4 MCQ Acids Bases and Salts
MCQ on Acids Bases and Salts Class 7
I. Multiple Choice Questions (1 Mark)
Select and write the most appropriate option out of the four options given
Question 1.
Which of the following are sour in taste ?
i) Common salt
ii) Curd
iii) Sugar
iv) Tamarind
A) (i) and (iii)
B) (i) and (ii)
C) (ii) and (iv)
D) (ii) and (iii)
Answer:
C) (ii) and (iv)
Question 2.
Select the odd one out.
A) Amla
B) Soap
C) Orange
D) Vinegar
Answer:
B) Soap
Question 3.
Select the incorrect statement.
A) Bases are bitter in taste.
B) Acids taste sour.
C) Acids feel soapy on touching.
D) Indicators are used to test whether a substance is acidic or basic.
Answer:
C) Acids feel soapy on touching.
Question 4.
Window cleaner contains ……….
A) ammonium hydroxide
B) sodium hydroxide
C) tartaric acid
D) calcium hydroxide.
Answer:
A) ammonium hydroxide
Question 5.
Ascorbic acid is more commonly known as ……….
A) mineral
B) potassium hydroxide
C) vitamin K
D) vitamin C
Answer:
D) vitamin C
Question 6.
When few drops of phenolphthalein are added to a solution of common salt, the solution
A) becomes pink in colour
B) remains colourless
C) turns orange in colour
D) turns green in colour.
Answer:
B) remains colourless
Question 7.
Red cabbage juice is ………… in colour, turns ………… in a basic medium and ………… an acidic medium.
A) purple, red, green
B) red, green, purple
C) purple, green, red
D) red, purple, green
Answer:
C) purple, green, red
Question 8.
Phenolphthalein gives ………… colour with soap solution.
A) pink
B) colourless
C) orange
D) green
Answer:
A) pink
Question 9.
Sodium hydroxide is not used for neutralising the hydrochloric acid present in the stomach during acidity because
A) it is a weak base and cannot neutralise acid
B) it is a strong base and it will burn the mouth and walls of stomach
C) it is not soluble in water hence cannot be swallowed
D) the acid present in stomach does not react with sodium hydroxide.
Answer:
B) it is a strong base and it will burn the mouth and walls of stomach
Question 10.
Methyl orange turns ………… in acidic solutions and ………… in basic solutions.
A) yellow, red
B) red, yellow
C) pink, blue
D) red, pink
Answer:
B) red, yellow
Question 11.
Sodium chloride solution is neutral in nature because
A) it is formed by complete neutralisation of a strong acid and a strong base
B) it is formed by the complete neutralisation of a weak acid and a weak base
C) it is formed by the incomplete neutralisation of a strong acid and a strong base
D) it is formed by the incomplete neutralisation of a weak acid and a weak base.
Answer:
A) it is formed by complete neutralisation of a strong acid and a strong base
Question 12.
Which of the following groups of samples will not show any change in colour with China rose indicator?
A) Lemon juice, curd and sugar solution
B) Distilled water, sodium chloride solution and sugar solution
C) Distilled water, window cleaner and lime water
D) Lime water, soap solution and lemon juice
Answer:
B) Distilled water, sodium chloride solution and sugar solution
Question 13.
Raghav was given two test tubes one containing water and other containing sodium hydroxide solution. To identify the solutions, which of the following indicators can be used by him?
i) Blue litmus
ii) Turmeric indicator
iii) Phenolphthalein
iv) Red litmus
A) (i) and (iv)
B) (ii), (iii) and (iv)
C) Only (iv)
D) Only (iii)
Answer:
B) (ii), (iii) and (iv)
Question 14.
Which of the following show no change with red litmus paper?
i) Sugar solution
ii) Soap solution
iii) Vinegar
iv) Lime water
v) Distilled water
vi) Soda water
A) (ii) and (iv)
B) (i), (iii) and (iv)
C) (iv), (v) and (vi)
D) (i), (iii), (v) and (vi)
Answer:
D) (i), (iii), (v) and (vi)
Question 15.
Which of the following turn China rose indicator green?
i) Window cleaner
ii) Salt solution
iii) Distilled water
iv) Lime water
(v) Lemon juice
vi) Sour milk
A) (i) and (iv)
B) (ii) and (iii)
C) (v) and (vi)
D) (ii) and (v)
Answer:
A) (i) and (iv)
Question 16.
Identify the correct statements.
i) With acidic and neutral substances, turmeric paper remains yellow.
ii) Phenolphthalein shows pink colour with distilled water.
iii) Blue litmus paper has no effect with lime water.
iv) Red litmus paper turns blue in glucose solution.
v) Turmeric paper changes to red colour in basic solutions.
A) (i), (ii) and (v)
(b) (iii) and (iv)
(c) (iii), (iv) and (v)
(d) (i), (iii) and (v)
Answer:
(d) (i), (iii) and (v)
II. Fill in the blanks
1. Curd changes China rose indicator to ………… in colour.
Answer: dark pink
2. Turmeric shows no effect on ………… and ………… solutions.
Answer: acidic, neutral
3. ………… can cause damage to buildings, historical monuments, plants and animals.
Answer: Acid rain
4. Window cleaner turns ………… litmus paper to ………… in colour.
Answer: red, blue
5. Turmeric stain turns ………… after washing with soap solution.
Answer: red
6. Soda water is ………… in nature.
Answer: acidic
7. Dry powder of baking soda has ………… effect on dry litmus paper.
Answer: no
8. Amino acids are the building blocks of …………
Answer: proteins
9. Salt formed by the neutralisation of a weak acid and a strong base is a …………
Answer: basic salt
10. Tea contains ………… acid.
Answer: tonnic
11. Our stomach contains ………… acid which helps in digestion.
Answer: hydrochloric
12. Baking soda solution turns turmeric to …………
Answer: red
13. ………… acids are weak acids present in plant and animal products.
Answer: organic
III. True or False
1. Litmus is a naturally occurring indicator.
Answer: True
2. Sodium hydroxide is used in the manufacture of soap.
Answer: True
3. Tamarind contains oxalic acid.
Answer: False
4. The sting of ants and bees contains formic acid.
Answer: True
5. Curd contains calcium hydroxide.
Answer: False
6. Grapes contain as corbic acid.
Answer: False
7. Phenolphthalein gives a pink colour with acidic solution.
Answer: False
8. Heat is always absorbed in neutralisation reaction.
Answer: False
9. The reaction mixture becomes cool when dilute sulphuric acid is added to lime water. [ ]
Answer: False
10. When right amount of hydrochloric acid is mixed with sodium hydroxide, the resulting solution is neither acidic nor basic.
Answer: True
11. Phenolphthalein is a natural acid-base indicator.
Answer: False
12. Sodium hydroxide remains colourless with phenolphthalein.
Answer: False
13. Carbon dioxide is dissolved in water to make sulphuric acid.
Answer: False
14. Acids react with metals to form salt and hydrogen gas.
Answer: True
15. Bases which are insoluble in water are called alkalies.
Answer: False
16. Potassium hydroxide is a weak base.
Answer: False
17. Acids react with carbonates to produce salt, water and carbon dioxide.
Answer: True
18. Neutralisation is an endothermic process.
Answer: False