Distinguish between the following:
(i) Acid and alkali
(ii) Base and alkali
(iii) Organic acid and mineral acid.

What is the effect of ant-bite? Explain its cure.

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?

Boojho, Paheli and their friend Golu were provided with a test, each containing China rose solution which was pink in colour. Boojho added 2 drops of solution 'A' in his test tube and got dark pink colour. Paheli added 2 drops of solution '8'to her test tube and got green colour. Golu added 2 drops of solution 'C' but could not get any change in colour. Suggest the possible cause for the variation in their results.

Nitesh was playing with his friends in the garden. Suddenly, Nitesh was stung by a honeybee and was in great pain. Immediately, his friends call his mother. She applied baking soda solution on the affected area and then took him to the doctor.
Read the above passage and answer the following questions:
(a) What could be the reason for this burning pain?
(b) Why did his mother applied baking soda solution on the affected area?
(c) What values are shown by Nitesh's friends?

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?

State the nature of following solution and give effects of these solution on litmus paper.
(i) Detergent solution
(ii) Lime water
(iii) Soft drink
(iv) Sugar solution
(v) Vinegar.

You are provided with four test tubes containing sugar solution, baking soda solution, tamarind solution, salt solution. Write down an activity to find the nature (acidic/basic/neutral) of each solution.