Effect on Indicators by Acids and Bases

Q. In what condition do vanilla, onion and clove lose their smell?

1. Neutral
2. Never
3. Acidic
4. Basic

Q. Olfactory indicator is a substance whose smell varies depending on whether it is mixed with an acidic or basic solution.

1. True
2. False

Q. Which of the following is true about anthocyanin pigments in red cabbage and rose petals?

1. They can act as indicators.
2. They can't be used as indicators.
3. They are blue in acidic and red in basic solutions.
4. They are made artificially.

Q.

Vanilla, clove and onion are __ indicators.

Q.

Dry $HCl$ gas changes the colour of the litmus paper.

1. True

2. False

Q.

What is the colour change observed in dil. HCl solution when phenolphthalein is added to it?

1. Colourless
2. Pink
3. Yellow
4. Green

Q.

What are pH indicators?

1. Aqueous solution of either salts of strong acids or strong bases.

2. Aqueous solution of either weak acids or weak bases.

3. Aqueous solution of either strong acids or strong bases.

4. Aqueous solution either salts of weak acids or weak bases.

Q.

Neutral solution changes the color of blue litmus to red.

1. True

2. False

Q.

Which of the following are used as an indicator for identifying acids and bases:

1. Litmus paper

2. Methyl orange

3. All are examples of indicators.

4. Tumeric

Q.

Identify the properties of a base

1. Bitter, ablitity to change colors in an indicator, and slippery.

2. Sour, ablitity to change colors in an indicator, shiny.

3. Shiny, ablitity to change colors in an indicator, and slippery.

4. Slippery, shiny, bitter.