Acids, Bases and Salts quiz

Acids taste:

Litmus is obtained from:

A base turns red litmus:

The acid present in curd is:

Turmeric turns red in:

Milk of magnesia contains:

China rose indicator turns basic solutions:

The products of neutralisation are:

An ant sting contains:

Which is a neutral substance?

Why is distilled water neutral? How would you verify it? (2 marks)

Name the acids present in orange, spinach and amla. (2 marks)

Why should we not taste substances to test whether they are acidic? (2 marks)

What happens when phenolphthalein is added to a basic solution? (2 marks)

Why is heat produced during neutralisation? What does it tell us? (2 marks)

Name two salts formed by neutralisation reactions. (2 marks)

What is the effect of an acid on blue litmus and on turmeric? (2 marks)

Why is baking soda used in an ant bite? (2 marks)

Name two substances you can use at home as indicators. (2 marks)

What is quicklime? Why is it added to soil? (2 marks)

A student adds dilute sodium hydroxide drop by drop to 10 mL of dilute hydrochloric acid with phenolphthalein. The solution turns pink after 12 drops. (i) Why was the solution colourless at first? (ii) What does the pink colour show? (iii) What would happen if one drop of acid is added again? (3 marks)

In a test, a student records: lemon juice turns blue litmus red; soap solution turns red litmus blue; salt solution changes neither. Of 9 substances tested, 4 were acidic and 3 basic. How many were neutral? What fraction were acidic? (3 marks)

A china rose test gave these results: vinegar dark pink, lime water green, sugar solution no change, washing soda green. Classify each and count how many are basic. (3 marks)

A farmer adds slaked lime to 3 fields whose soil tested as acidic, basic and neutral. In which field(s) is lime useful? What should be added to the basic field? Explain. (3 marks)

Write the word equations for neutralisation of (i) hydrochloric acid with sodium hydroxide (ii) sulphuric acid with calcium hydroxide (iii) acid in the stomach with magnesium hydroxide. (3 marks)

Read the passage and answer the questions. Boojho had a stomach ache after a heavy meal. His mother gave him milk of magnesia and he felt better. (i) What caused the discomfort in his stomach? (ii) What type of substance is milk of magnesia? (iii) What reaction gave him relief? (5 marks)

Read the passage and answer the questions. Paheli spilled a little curry with turmeric on her white shirt. When it was washed with soap, the yellow stain turned red. It became yellow again on rinsing with lots of water. (i) Why did the stain turn red? (ii) What is soap: acidic or basic? (iii) Why did the colour change back after rinsing? (5 marks)

Read the passage and answer the questions. A factory near a river released waste water containing acids. Fish in the river began to die. (i) Why did the fish die? (ii) How can the waste be treated before release? (iii) Name the reaction involved. (5 marks)

Read the passage and answer the questions. A student prepared an indicator by soaking china rose petals in warm water and tested lemon juice, soap solution and water. (i) What colour will lemon juice give? (ii) What colour will soap solution give? (iii) What will water show? (5 marks)

Read the passage and answer the questions. A soil sample from a field was found to be acidic. Plants were not growing well. (i) Why does excess acidity harm plants? (ii) Which substance should be added? (iii) Which substance is added if the soil is basic? (5 marks)

Describe an activity to show neutralisation of an acid with a base using phenolphthalein. Draw the set-up and explain the colour changes. (6 marks)

Explain three natural indicators (litmus, turmeric, china rose), how each is obtained and the colour each shows in acids and bases. Draw a labelled diagram of making turmeric paper. (6 marks)

Explain four applications of neutralisation in daily life with examples. (6 marks)

Distinguish between acids and bases on the basis of taste, touch, effect on litmus, turmeric and china rose, and give two examples each. (6 marks)

Draw a flowchart to identify an unknown solution as acidic, basic or neutral using red and blue litmus. Explain each step. (6 marks)