Acids bases and salts

Before to solve these questions of chapter 2 science ‘Acids Bases and Salts’ students have to solve first chapter questions. To get the questions of chapter-1 CLICK HERE-

                                        Chemistry Class Xth

                                    Ch-2 Acids, Bases and Salts

Multiple Choice Questions

1. What is the common name of CaOCl₂?(a)Bleaching powder(b)Baking soda(c)Washing soda(d)Lime water
2. Which one will turn red litmus blue?(a)Vinegar(b)Lemon juice(c)Soft drinks(d)Baking soda solution
3. 10 ml of a solution of NaOH is found to be completely neutralised by 8ml of a given solution of HCL. If we take 20ml of the same solution of NaOH ,the amount of HCL solution required to neutralise it will be:(a)4ml(b)8ml(c)12ml(d)16ml
4. A solution reacts with zinc granules to give a gas which burns with a pop sound .The solution contains:(a)Mg(OH)₂(b)Na₂CO₃(c)NaCl(d)HCL
5. The indicator which produces a pink colour in an alkaline solution is:(a)Methyl orange(b)Turmeric paper(c)Phenolphthalein(d)Litmus paper
6. The discomfort caused by indigestion due to overeating can be cured by taking:(a)Vinegar(b)Lemon juice(c)Baking soda(d)Caustic soda
7. One of the following is not an organic acid.  This is :(a)Ethanoic acid(b)Formic acid(c)Citric acid(d)Carbonic acid
8. One of the following is a medicine for indigestion. This is:(a)Sodium hydroxide(b)Manganese hydroxide(c)Magnesium hydroxide(d)Potassium hydroxide
9. Bee sting contains:(a)An acidic liquid(b)A salt solution(c)An alkaline liquid(d)An alcohol
10. Fresh milk has a PH of 6. When milk changes into curd ,the PH value will :(a)Become 7(b)Become less than 7(c)Become more than 7(d)Remain unchanged
11. The salt which will give an acidic solution on dissolving in water is:(a)KCL(b)NH₄CL(c)Na₂CO₃(d)CH₃COONA
12. The number of molecules of water of crystallization present in washing soda crystals is:(a)Five(b)Two(c)Ten(d)Seven
13. Plaster of paris is prepared by heating one of the following to a temperature of 100⁰C. this is:(a)CaSO₃.2H₂O(b)CaCl₂.2H₂O(c)CaCO₃.2H₂O(d)CaSo₄.2H₂O
14. A solution turns red litmus blue, its PH is likely to be(a)1(b)4(c)5(d)10
15. A solution reacts with crushed eggs-shells to give gas that turns lime -water milky. The solution contains(a)NaCl(b)HCL(c)LiCl(d)KCl

Objective Answer

1. A
2. D
3. D
4. D
5. C
6. C
7. D
8. C
9. A
10. B
11. B
12. C
13. D
14. D
15. D

Two marks questions

1. why should curd and sour substances not be kept in brass and copper vessels?
2. Why do HCl , HNO₃ etc. show acidic characters in aqueous solutions while solutions of compounds like alcohol and glucose do not show acidic character?
3. Why does an aqueous solution of an acid conduct electricity?
4. Why does dry HCl gas not change the colour of the dry litmus paper?
5. While diluting an acid, why it is recommended that the acid should be added to water and not water to the acid?
6. How is the concentration of hydronium ions affected when a solution of an acid is diluted?
7. How is the concentration of hydroxide ions affected when excess base is dissolved in a solution of sodium hydroxide?
8. What will happen if a solution of sodium carbonate is heated? Give the equation of the reaction involved?
9. Write an equation to show the reaction between plaster of paris and water.
10. Why does distilled water not conduct electricity , whereas rain water does?
11. Why do acid not show acidic behaviour in the absence of water?
12. Plaster of Paris should be stored in a moisture-proof container .explain why ?
13. What is a neurtralisation reaction ? Give two examples.
14. Give two important uses of washing soda and baking soda.
15. A milk adds a very small amount of baking soda to fresh milk.(i)Why does he shift the PH of the fresh milk  from 6 to slightly alkaline?(ii)Why does this milk take a long time to set as curd?

3 marks questions

1. Metal compound A reacts with dilute hydrochloric acid to produce effervescence. The gas evolved extinguishes a burning candle .  write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride.
2. What will you observe when a small amount of copper oxide is added in a beaker containing dilute hydrochloric acid?
3. To an aqueous solution of sodium hydroxide a few drops of phenolphthalein were added .What do you observe, to this solution when small amount of dil. HCl was added ? explain your answer.
4. What is rock salt? Why is it brown in colour?
5. Why is washing soda also called basic salt? what are its uses?
6. How do metal carbonates and metal hydrogen carbonate react with acids? Give their chemical equations.
7. Write chemical name, chemical formula of bleaching powder. Write its chemical reaction and also write its two uses.
8. Write chemical name, chemical formula of caustic soda. write its chemical reaction and two uses.
9. Five solutions A, B, C, D and E when tested with universal indicator showed pH as,(a)Neutral (b)Strongly alkaline (c)Strongly acidic (d)Weakly acidic(e)Weakly alkaline. Arrange the pH in increasing order of hydrogen ion concentration.
10. What are olfactory indicators? Write an example, also Write the name of two natural indicator.

5 marks questions

1. What is plaster of Paris? Write its chemical name and chemical formula. Also write the chemical reaction and its two uses.
2. Write balanced chemical equations for the following: (a)Chlorine gas is passed through dry slaked lime. (b)Bleaching powder is kept in open air.(c)Sodium bicarbonate is reacts with dilute hydrochloric acid.(d)Electricity is passed through brine.(e)Formation of baking soda from sodium chloride.