Page 62 - CT&AI_CLasa_7_Part_1

6. Which step helps confirm a substance is
neutral? (Decomposition)

(a) Test with only red litmus paper.

(b) Test with only blue litmus paper.
3. Filtering the rose 4. Putting the
(c) Test with both red and blue litmus water extract crushed petals in
hot water
papers.
Identify the correct sequence of steps that
(d) Heat the substance strongly. should be followed to prepare the indicator.
(Algorithmic Thinking)
7. Three unknown liquids A, B, and C are tested (a) 2 1 4 3
using blue litmus, red litmus, and onion
indicator. The observations are shown below: (b) 2 1 3 4

Test A B C (c) 1 3 2 4

Blue litmus Red No change No change (d) 2 3 1 4

Red litmus No change Blue No change 9. Which algorithm best represents neutralisation?

Onion smell Same Disappears Same (Algorithmic Thinking)

Which liquid is neutral? (Decomposition) (a) Acid + Acid Salt

(a) A (b) Base + Base Water

(b) B (c) Acid + Base Salt + Water + Heat

(c) C (d) Acid + Base Base

(d) Both A and B 10. Choose the correct algorithm to test a
substance using litmus:
8. A student wants to prepare an acid-base
indicator using red rose petals. Some steps (Algorithmic Thinking)
are shown below: (a) Take substance Add water
Heat

(b) Take litmus Add substance
Observe colour change

(c) Mix substances Wait Smell
1. Crushing the 2. Washing the
petals rose petals (d) Taste Observe Record

60 Computational Thinking-7 (Science)