Question

Q 1. Why cannot common indicators determine the pH value of a solution? Q 2. What will you observe when: (i) Red litmus is introduced into a solution of sodium sulphate. (ii) Methyl orange is added to dil HCl. (iii). Blue litmus is introduced into a solution of ferric chloride Q 3. Write equations for the following reactions (i) Dilute sulphuric acid reacts with zinc granules (ii) Dilute hydrochloric acid reacts with magnesium ribbon. (iii) Dilute sulphuric acid reacts with aluminum powder. Q 4. A first aid manual suggests that vinegar should be used to treat wasp sting and baking soda for bee stings. (a) What does this information tell you about the chemical present in the wasp sting? (b) If there were no baking soda in the house, what other substance would you use to treat as stings? Q 5. What is the action of red litmus on (i) Dry ammonia gas (ii) Solution of ammonia gas in water? Q 6. Metal compound ‘A’ reacts with dilute hydrochloric acid to produce effervescence. The gas evolved to extinguish a burning candle. Write a balanced chemical equation for the reaction, if one of the compounds formed is calcium chloride. Q 7. Give the reason for the following statement: Rainwater conducts electricity but distilled water does not. We feel a burning sensation in the stomach when we overeat. A tarnished copper vessel regains its shine when rubbed with lemon. Q 8. You have two solutions ‘A’ and ‘B’. The pH of solution ‘A’ is 6 and pH of solution ‘B’ is 8. Which solution has more hydrogen ions concentration? Which is acidic and which one is basic? Q 9. A milkman adds a very small amount of baking soda to fresh milk. (a) Why does he shift the pH of the milk from 6 to slightly alkaline? (b) Why does this milk take a long time to set a curd? Q 10. Under what soil conditions do you think a farmer would treat the soil of his field with quicklime (calcium oxide) or slaked lime (calcium hydroxide) or chalk (calcium carbonate).

Answer 1

Answer:

please make your question short