Natural Indicators — Homi Bhabha Class 6 Chemistry MCQs with Solutions
Free Homi Bhabha Class 6 Chemistry Natural Indicators MCQs with step-by-step solutions (10 questions). Part of Acids, Bases and Neutralization. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Natural Indicators · easy · theory
A substance that changes its colour to show whether something is an acid or a base is called a/an:
A. Solvent
B. Indicator ✓ Correct
C. Filter
D. Mixture
Solution: An indicator changes colour in acids and bases, so we use it to tell them apart.
Q2 — Natural Indicators · easy · theory
Litmus, a common natural indicator, is taken from a plant-like living thing called:
A. Mango tree
B. Rose
C. Lichen ✓ Correct
D. Grass
Solution: Litmus is extracted from lichens, which grow on rocks and tree bark.
Q3 — Natural Indicators · easy · theory
When blue litmus paper is dipped in an acid, its colour changes to:
A. Yellow
B. Green
C. Red ✓ Correct
D. Black
Solution: Acids turn blue litmus red. That is the simple test for an acid.
Q4 — Natural Indicators · easy · theory
Red litmus paper is dipped in a base. Its colour changes to:
A. Blue ✓ Correct
B. Colourless
C. Red
D. Pink
Solution: Bases turn red litmus blue, which is the test for a base.
Q5 — Natural Indicators · medium · theory
Turmeric (haldi) is yellow. When soap solution (a base) touches it, the turmeric turns:
A. Colourless
B. Red ✓ Correct
C. Green
D. Blue
Solution: Turmeric is a natural indicator that turns reddish in a base, but stays yellow in an acid.
Q6 — Natural Indicators · medium · theory
Which of these can be used as a natural indicator?
A. Sand
B. Common salt
C. Sugar
D. China rose (gudhal) petals ✓ Correct
Solution: China rose petals give a coloured juice that changes colour in acids and bases; salt, sugar and sand do not.
Q7 — Natural Indicators · medium · theory
China rose (gudhal) indicator gives a dark pink (magenta) colour with acids. With bases it turns:
A. Green ✓ Correct
B. Dark pink
C. Yellow
D. Red
Solution: China rose indicator turns dark pink in acids and green in bases.
Q8 — Natural Indicators · medium · theory
Purple red-cabbage juice is used as an indicator. In an acid it turns:
A. Yellow
B. Green
C. Deep blue
D. Red / pink ✓ Correct
Solution: Red-cabbage juice turns red or pink in acids and greenish in bases.
Q9 — Natural Indicators · hard · theory
A drop of lemon juice is placed on yellow turmeric paper. What is most likely to happen?
A. It stays yellow ✓ Correct
B. It turns red
C. It turns green
D. It turns blue
Solution: Turmeric only changes colour with a base. Lemon juice is an acid, so the paper stays yellow.
Q10 — Natural Indicators · hard · theory
Which statement about litmus is completely correct?
A. A base turns blue litmus red
B. An acid turns blue litmus red, and a base turns red litmus blue ✓ Correct
C. An acid turns red litmus blue
D. Both acids and bases turn litmus green
Solution: Acids change blue litmus to red; bases change red litmus to blue. Litmus does not turn green.