What happen to the dry litmus paper used to test the nature of solid baking soda. Give reason of your answer. Open Answer »
If you are given a colourless liquid, how will you find out if it is an acid or a base without tasting it? Open Answer »
Give two uses of the following acids. a. Nitric acid b. Hydrochloric acid c. Sulphuric acid Open Answer »
Paheli observed that most of the fish in the pond of her village were gradually dying. She also observed that the waste of a factory in their village is flowing into the pond which probably caused the fish to die. (a) Explain why the fish were dying. (b) If the factory waste is acidic in nature, how can it be neutralised? Open Answer »
You are provided with three test tubes A, B and C as shown in figure with different liquids. What will you observe when you put (a) a piece of blue litmus paper in each test tube? (b) a piece of red litmus paper in each test tube? (c) a few drops of phenolphthalein solution to each test tube? Open Answer »
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. Open Answer »
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? Open Answer »
Boojho, Paheli and their friend Golu were provided with a test tube each containing China rose solution which was pink in colour. Boojho added two drops of solution ‘A’ in his test tube and got dark pink colour. Paheli added 2 drops of solution ‘B’ 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. Open Answer »