Consider the following statements:
(i) Both acids and bases change colour of all indicators.
(ii) If an indicator gives a colour change with an acid, it does not give a change with a base.
(iii) If an indicator changes colour with a base, it does not change colour with an acid.
(iv) Change of colour with an acid and a base depends on the type of the indicator.
Which of the above statements is/are correct?

Phenolphthalein is a synthetic indicator and its colours in acidic and basic solutions respectively are

When the soil is too basic, plants do not grow well in it. To improve its quality, what must be added to the soil?

Neutralisation reaction is a

Which of the following is an acid-base indicator?

When an acid mixed with a base, a __________ reaction takes place.

Acetic acid is present in __________ while __________ is present in lemon.

Excessive use of chemical fertilisers make the soil __________

Hydrochloric acid + Sodium hydroxide \(\longrightarrow\) __________

Acids turn blue litmus ________

Lime water turns red litmus blue.

Common salt dissolved in water turns blue litmus red.

Phenolphthalein is a natural indicator.

Calamine can be used to treat ant's sting.

Lemon water is basic in nature.

Name the reaction when an acid is mixed with base.

Which acid is injected into our body by an ant sting that causes pain?

Name the salt formed when hydrochloric acid reacts with sodium hydroxide solution (a base).

Write two basic substances which we use in our daily life.

Name one acid which is responsible for acid rain.

State differences between acids and bases.

Name the source from which litmus solution is obtained. What is the use of this solution?

Is the distilled water acidic/basic/neutral? How would you verify it?

Dorji has a few bottles of soft drink in his restaurant. But unfortunately, these are not labelled. He has to serve the drinks on the demand of customers. One customer wants the acidic drink, another wants basic and third one wants the neutral drink. How will Dorji decide which drink is to be served to whom?

Look at the given reaction. 
Hydrochloric acid + Sodium hydroxide (base) \(\longrightarrow\) Sodium chloride (salt) + Water
Sodium chloride formed in this reaction remains in solution form. Can we get solid sodium chloride from this solution? Suggest a method (if any).

A farmer was unhappy because of his low crop yield. He discussed the problem with an agricultural scientist and realised that the soil of his field was either too acidic or too basic. What remedy would you suggest the farmer to neutralise the soil?

One day Rahul's mother after taking meal felt pain and irritation in her stomach. His father was out of station. Rahul was an intelligent boy. He remembered his teacher's statement and gave his mother some baking soda solution which gave her a relief from pain and irritation of the stomach.
Read the above passage and answer the following questions.
(a) Which information given by Rahul's teacher that helped him to select the baking soda as a remedy?
(b) Why he selects baking soda as a cure?
(c) What values are shown by Rahul?