Acids,Bases And Salts -LS-1

What colour do the methyl orange indicators turn when added to a base or alkali (such as sodium hydroxide) ?

What colour do the litmus indicators turn when added to a base or alkali (such as sodium hydroxide) ?

What colour do red cabbage extract indicators turn when added to a base or alkali (such as sodium hydroxide) ?

What happens when a blue litmus paper is dipped into an acid solution? (such as hydrochloric acid) ?

• Litmus paper turns red

• Litmus paper turns green

• Colour of litmus paper vanishes out

• No change in the colour of litmus paper

What colours do the methyl orange indicators turn when added to an acid (such as hydrochloric acid) ?

• red

• green

Name an indicator which is red in acid solution but turns blue in basic solution.

• Litmus

• Methyl orange

• Phenolphthalein

• China Rose

Name an indicator which is pink in alkaline solution but turns colourless in acidic solution.

• Phenolphthalein.

• Methyl orange

• Litmus

When a solution is added to a cloth strip treated with onion extract, then the smell of onion cannot be detected. State whether the given solution contains an acid or a base.

• Base.

• Acid

When a solution is added to vanilla extract, then the characteristic smell of vanilla cannot be detected. State whether the given solution is an acid or a base.

• Acidic

• basic

What gas is liberated when hydrochloric acid reacts with a metal?

• a) Oxygen

• b) Nitrogen

• c) Hydrogen

• d) Carbon dioxide

Answer explanation