Question

1. Why are all alkalis bases, but not all bases alkalises? 2. Why does nitric acid not produce hydrogen, when treated with metals? 3. Metal hydroxides and metal oxides are called bases. Explain and support your answer by balanced chemical equations. 4. Match the acids given in Column (A) with their correct sources given in Column (B). Column A Column B (a) Lactic acid (i) Tomato (b) Acetic acid (ii) Lemon (c) Citric acid (iii) Vinegar (d) Oxalic acid (iv) Curd 5. What happens when nitric acid is added to an egg shell? 6. Give two examples of : (i) soluble bases (ii) partially soluble bases (iii) insoluble bases. 7. Arrange the following solutions in order of decreasing H+(aq) ions concentration. (i) ammonium hydroxide (ii) gastric juice (iii) vinegar (iv) sodium hydroxide 8. Why does a bee sting cause pain and itching? What is the common remedy to overcome such a pain? 9. Do basic solutions also have H+(aq) ions? If yes, then why are these basic? 10. Two solutions R and Q are tested with universal indicator. The solution P turns red, whereas solution Q turns orange. Which solution : (i) is more acidic; (ii) has more pH. 11. Name the acid present in ant sting and give its chemical formula. Also give the common method to get relief from the discomfort caused by the ant sting. [HOTS] 12. How would you distinguish between baking powder and washing soda by heating? [HOTS] 13. A sulphate salt of Group 2 element of the Periodic Table is a white, soft substance, which can be moulded into different shapes by making its dough. When this compound is left in open for some time, it becomes a solid mass and cannot be used for moulding purposes. Identify the sulphate salt and why does it show such a behaviour? Give the reaction involved.

Answer 1

Answer:

1: Because some bases are soluble in water and some bases are not soluble in water. eg.(base)NaOH is an alkalies because it is soluble in water other bases like NH4OH , Al(OH)3 are soluble in water.