class 7 Acid bases and salts revision 2

Products of a neutralisation reaction are always:

(a) an acid and a base

(b) an acid and a salt

(c) a salt and water

(d) a salt and a base

Turmeric is a natural indicator. On adding its paste to acid and base separately, which colours would be observed.

(a) Yellow in both acid and base

(b) Yellow in acid and red in base

(c) Pink in acid and yellow in base

(d) Red in acid and blue in base

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

(a) red and blue

(b) blue and red

(c) pink and colourless

(d) colourless and pink

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

(a) Organic matter

(b) Quick lime

(c) Slaked lime

(d) Calamine solution

Which of the following set of substances contain acids?

(a) Grapes, lime water

(b) Vinegar, soap

(c) Curd, milk of magnesia

(d) Curd, vinegar

Which of the following is an acid-base indicator?

(a) Vinegar

(b) Lime water

(c) Turmeric

(d) Baking soda

The reaction between an acid and a base to form salt & water along with the evolution of heat is called