Indicator

Q.

When pH paper is dipped in a solution, a light green colour is observed. What would be the pH value of the solution?

1. pH 5

2. pH 6

3. pH 7

4. pH 8

Q.

Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution? Explain.

Q.

Indicators are substances that indicates whether the substance is acidic in nature.

1. True

2. False

Q. Match the following indicators to the respective colour change in the acidic or basic medium:

1. Yellow (basic)
2. Colourless (acidic)
3. Red (acidic)
4. Green (basic)

Q. Two solutions X and Y are tested with universal indicator. Solution X turns orange whereas solution Y turns red. Which of the solutions is a stronger acid?
[1 Mark]

Q. Phenolphthalein is a colourless indicator that turns pink in basic solution.

1. False
2. True

Q. Which of the following indicator gives more than two colours?

1. Phenolphthalein
2. Turmeric
3. Universal indicator
4. Methyl orange

Q. Litmus turns red in an acidic solution and blue in a basic solution.

1. False
2. True

Q. China rose indicator in acidic solution changes its colour to ________________.

1. yellow
2. dark pink
3. green
4. blue

Q. Match the following indicators to the respective colour change in the acidic or basic medium:

1. Red(Acidic)
2. Yellow(Basic)
3. No color(Acidic)
4. Pink(Basic)

Q. If vapours of dry ammonia gas are brought into contact with red litmus paper, what will happen to the colour of the litmus paper?

1. Litmus paper turns blue
2. Litmus paper turns pink
3. No change in the litmus paper
4. Litmus paper turns yellow

Q. Identify the colour observed when red cabbage extract is added to the acids and bases.

1. Strong base
2. Weak acid
3. Strong acid
4. Light pink
5. Dark pink
6. Pale yellow