ACIDS, BASES AND SALTS
1.Multiple choice questions
1 The acid having highest hydrogen ion concentration is one with:
(a) pH=2.5 (b) pH =1.8 (c) pH =7 (d) pH =!0
2 Which of the following salts does not contain water of crystallization?
(a) Blue vitriol (b) Baking Soda (c) Washing Soda (d) Gypsum
3 In general , salts :
(a) are ionic compounds (b) contain hydrogen ions (c) contain hydroxide ions (d) turns blue litmus red
4 The pH of gastric juices released during digestion is :
(a) less than 7 (b) more than 7 (c) equal to 7 (d) equal to 0
5 Which of the following is (are) true when HCI (g) is passed through water?
(a) It does not ionize in the solution as it is a covalent compound.
(b) It ionizes in the solution
(c) It gives doth hydrogen and hydroxyl ion in the solution.
(d) It forms hydronium ion in the solution due to the combination of hydrogen ion with water molecule.
(a) only (b) (c) only (c) (b) and (c) (d) (c) and (d)
2. Assertion Reasoning
The following questions consists of two statements- Assertion (A) and reason (R). answer these questions selecting the appropriate option given below:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and Rare true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
1 Assertion (A): The aqueous solution of glucose and alcohol do not show acidic character.
Reason (R):Aqueous solution of glucose and alcohol do not give H+ ions.
2 Assertion (A): HCI gas does not change the colour of dry blue litmus paper.
Reason (R): HCI gas dissolves in the water present in wet litmus paper H+ ions.
3. Match the following
Column I Column II
1. Plaster of Paris a. CaSO4.2H2O
2. Bleaching Powder b. Na2CO3 . 10H2O
3. Washing Soda c. CaSO4. ½ H2O
4. Baking Soda d. CaOCI2
5. Gypsum e. NaHCO3
4. Answer the following questions:
1. What are the general characteristics of acids?
2. What will be the action of the following substances on litmus paper (a) Dry HCl gas (b) moistened NH3 gas (c) lemon juice (d) carbonated soft drink (e) curd (f) soap solution.
3 Name the acid present in the ant sting. Also give the common method to get relief from the discomfort caused by the ant sting.
4 What happens when anacid is added to egg shell?
5 A student prepared solutions of an acid and a base in two separate beakers. She forgot to label the beakers and litmus paper is not available in the lab. Since both the solutions are colorless how will she distinguish between the two?
6 What is aqua regia? Write one application.
7 Tooth enamel is one of the hardest substances in our body. How does it undergo damage due to eating sweets and chocolates? How do tooth pastes prevent this damage?
8 Salt A commonly used in bakery products on heating gets converted into another salt B which itself is used for removal of hardness of water and a gas C is evolved. The gas C when passed through lime water turns milky. Identify A, B and C.
9 When Zinc metal is treated with a dilute solution of strong acid, agas is evolved. Name the gas and write the chemical equation of the reaction involved and also write a test to detect the gas formed.
10 What are olfactory indicators? Give 2 examples.
11 A dry pellet of a common base B, when kept in open absorbs moisture and turns sticky. The compound is also a byproduct of Chlor-alkali process. Identify B. What type of reaction occurs when B is treated with acidic oxide? Write a
balanced chemical equation for one such solution.
12 A sulphate salt which is white soft substance is used in making toys. When this compound is left in open for some time, it becomes a solid mass which cannot be used for molding purposes. Identify
the salt, why does it show such a behavior? Give the reaction involved.
13 A white powder is added while baking breads and cakes to make them soft and fluffy. Write the name of the powder. Name its main ingredients. Write the chemical reaction taking place when the powder is heated during baking.
14 On passing excess carbon dioxide gas through lime water,it first turns lime water milky and then becomes colourless.Explain why? Write all the chemical equations of the reactions involved.
15 What happens when a solution of sodium hydrogen carbonate is heated? Write the chemical equation of the reaction involved.
16 State the chemical property in each case on which the following uses of baking soda are based :-
i) as an antacid ii) as a constituent of baking powder.
17 A compound X of sodium forms a white powder. It is a constituent of baking powder and is used in some antacid prescriptions. When heated, X gives out a gas and steam. The gas forms a white precipitate with limewater. Write the chemical formula and name of X and the chemical equation for its decomposition on heating. What is its role in baking powder and in antacids
18 How is common salt prepared from sea water?
19 a) What is pH scale and how is it related to hydronium ion concentration? b) Fresh milk has a pH of 6. When it changes into curd, will its pH value increase or decrease? Why?
20 Explain why an aqueous solution of sodium sulphate is neutral while an aqueous solution of sodium carbonate is basic in nature.
21 Why do acidic or basic solutions conduct electricity?
22 A metal compound ‘A’ reacts with dilute Sulphuric acid to produce a gas which extinguishes a burning candle. Identify the compound ‘A’ and a gas produced. Write a balanced chemical equation for the reaction if one of the compounds formed in the reaction is sodium sulphate.
23 A gas X reacts with lime water and forms a compound Y which is used as a bleaching agent in chemical industry. Identify X and Y.Give the chemical equation of the reactions involved.
24. Why does 1 M HCl solution have a higher concentration of H + ions than 1M CH3COOH?
25. Crystals of a substance changed their colour on heating in a closed test tube but regained it after some time when they were allowed to cool down. Name the substance and write its formula. Also explain the phenomenon involved.
5. Fill in the Blanks:
1. A _____________ indicator is a mixture of several indicators.
2. Acids are _____________ in taste and change the colour of blue litmus to ________________
3. The strength of acids and base depends on the no of _________________ ions and __________________ions produced respectively, when dissolved in water. Acids like HCIO4 which dissociate almost completely in water are called ________________ acids.
4. The salts of strong acid and strong base are ______________ with pH value of 7.
Please click on below link to download CBSE Class 10 Chemistry Acids Bases And Salts Worksheet Set H
