Chapter-2 ACIDS, BASES AND SALTS NCERT Exemplar

1. What occurs when an acid solution and a base solution are combined in a test tube?

(i)  The solution's temperature rises.

(ii) The solution's temperature drops.

(iii) The solution's temperature stays constant

 (iv) Salt is formed in the following ways:

(a) (i) only                 (b) (i) and (iii)

 (c) (ii) and (iii)         (d) (i) and (iv)

2. Red litmus solution turns blue when watery solution is added. Which of the following solutions would undo the change if added excessively?

 (a) Baking soda                                                 (b) Lime

(c) A solution of ammonium hydroxide      (d) Hydrochloric acid 

3. On a humid day, the hydrogen chloride gas is often prepared by passing it through a guard tube containing calcium chloride. The calcium chloride used in the guard tube serves as a

(a) absorb the gas that has evolved

(b) make the gas wet

(c) remove water vapour from the gas.

(d) take in Cl- ions from the gas being generated.

4. Which of the following salts doesn't have crystallisation water in it?

(a) Hatred in blue.

(b) Baking soda

(c) Bleach soda

(d) Gypsum 

5. As sodium carbonate is a salt of sodium, it is a basic salt.

(a) Strong bases and acids

(b) Weak bases and acids

(c) powerful acid and feeble base

(d) a strong base and a weak acid

6. Tooth enamel contains calcium phosphate. Its character is

(a) essential

(b) Acidic

(c) impartial

(d) Amphoteric

7. Water and a soil sample are combined, then allowed to settle. The pH paper turns orange-yellow when exposed to the clear supernatant solution. Which of the following causes this pH paper's colour to turn greenish-blue?

(a) Lemon juice

 (b) Vinegar

(c) Regular salt

(d) An antacid.

8. Which of the following provides the right ranking of acid strength in ascending order?

(a) Acetic acid, hydrochloric acid, and water

(b) Acetic acid, water, and hydrochloric acid

(c) Water, Hydrochloric acid, and Acetic acid

(d) Water, acetic acid, and hydrochloric acid

9. If a few drops of a concentrated acid accidentally spills over the hand of a student, what should be done?

(a) Wash the hand with saline solution

(b) Wash the hand immediately with plenty of water and apply a paste of sodium hydrogen carbonate

(c) After washing with plenty of water apply a solution of sodium hydroxide on the hand

(d) Neutralise the acid with a strong alkali

10. Acetic acid produces a gas when sodium hydrogen carbonate is introduced. Which of the following statements concerning the fuels' evolution is accurate?

(i) The lime water becomes milky.

(ii) It puts out a blazing splinter (ii).

(iii) It dissolves in a sodium hydroxide solution.

(iv) It smells strongly.

(a) (i) and (ii)               (b) (i), (ii) and (iii)

(c) (ii), (iii), and (iv)      (d) (i) and (iv)

11. Common salt besides being used in the kitchen can also be used as the raw material for making:

(i) washing soda    (ii) bleaching powder

(iii) baking soda      (iv) slaked lime

(a) (i) and (ii)

(b) (i), (ii) and (iv)

(c) (i) and (iii)

(d) (i), (iii) and (iv)

12. Sodium hydrogen carbonate and sodium bicarbonate are two ingredients in baking powder.

(a) Hydrochloric acid

(b) Tartaric acid

(c) Acetic acid

(d) Sulfuric acid 

13. Regular tooth brushing is indicated to prevent tooth decay. The typical toothpaste's composition is

(i) Acidic         (b) impartial

(c) Basic          (d) Destructive

14. Which of the following statements regarding an acid and base aqueous solution is true?

(i) The acid is stronger the higher the pH.

(ii) The acid is weaker the higher the pH.

(iii) The stronger the base, the lower the pH.

(iv) The base gets weaker as the pH drops.

(a) (i) and (iii)       (b) (ii) and  (iii)

(c) (i) and (iv)        (d) (ii) and (iv)

15. The pH of the gastric juices released during digestion is

(a) less than 7

(b) more than 7

(c) equal to 7

(d) equal to 0

16. Which of the following happens when a little acid is introduced to water?

(i) Ionizationa

(ii) Neutralization (ii)

(iii) Diluting

(iv) Production of salt

(a) (i) and (ii)         (b) (ii) and (iii)

(c) (ii) and (iii)        (d) (ii) and (iv)

17. Which of the following can a student who is blind use as an acid-base indicator?

(a) Litmus test              (b) Curcumin

(c) Vanilla flavouring    (d)Petunia leaves

18. Which of the following materials won't release carbon dioxide when treated with weak acid?

(a) A marble            (b) Limestone

(c) Baking soda        (d) Lime

19. Which of the following statements is true?

(a) Lime juice              (b) Human blood (b)

(c) Lime water             (d) Antacids

20. The following device was created in an effort to show electrical conductivity across an electrolyte. The setup was (Figure 2.1). Which of the aforementioned statements is true?

(i) Bulb will not glow because the electrolyte is not acidic

(ii) Bulb will glow because NaOH is a strong base and furnishes ions for conduction.

(iii) Bulb will not glow because the circuit is incomplete

(iv) Bulb will not glow because it depends upon the type of electrolytic solution

(a) (i) and (iii)                (b) (ii) and (iv)

(c) (ii) only                    (d) (iv) only

21. Which of the following methods is used to dissolve gold?

(a) Chlorine dioxide            (b) Sulfuric acid

(c) Nitrous oxide                 (c)Aqua regia.

22. Which of the following is a mineral acid and which is not?

(a) Chlorine dioxide                 (b) Acidic citrus

(c) Sulfuric acid                        (d) Sodium nitrate

23. Which of the following is not a base, number?

(a) NaOH                            (b) KOH

(c) NH4OH                          (d) C2H5 OH

24. Which of the above assertions is untrue?

(a) salt, water, and carbon dioxide are produced when all metal carbonates react with acid.

(b) Salt and acid are produced whenever metal oxides interact with water.

(c) Salt and hydrogen are produced when certain metals react with acids.

(d) Water reacts with some non-metal oxides to create an acid.

25. Match the chemical substances given in Column (A) with their appropriate application given in Column (B)

Column (A)                                                                                Column (B)

(A) Bleaching powder                                                    (i) Preparation of glass

(B) Baking soda                                                                           (ii) Production of H2 and Cl2

(C) Washing soda                                                           (iii) Decolourisation

(D) Sodium chloride                                                       (iv) Antacid

(a) A—(ii), B—(i), C—(iv), D—(iii)

(b) A—(iii), B—(ii), C—(iv), D—(i)

(c) A—(iii), B—(iv), C—(i), D—(ii)

(d) A—(ii), B—(iv), C—(i), D—(iii)

26. Equal amounts of sodium hydroxide and hydrochloric acid solutions at the same concentration are combined, and the resulting solution's pH is assessed using a pH paper. What colour would be the result? (You can refer to the colour palette in Figure 2.2.

(a) Red

(b) Orange

(c) Greenish yellow

(d) Blue

27. Which of the following statements regarding HCl (g) passing through water is/are true?

(i) Because it is a covalent molecule, it does not ionise in the solution.

(ii) It ionises in the solution .

(iii) It provides the solution with both hydrogen and hydroxyl ions.

(iv) The interaction of the hydrogen ion with the water molecule causes the formation of the hydronium ion in the solution.

(a) (i) alone                              (b) only  (iii)

(c) (ii) and  (iv)                          (d (iii), and (iv)

28. Which of the following claims about acids is true?

(a) Bitter and turning red litmus test into blue

(b) Make sour and turn red litmus paper blue.

(c) Make sour and turn blue litmus paper red.

(d) Be angry and turn blue litmus paper crimson.

29. Which of the following ingredients can be found in diluted hydrochloric acid in water?

(a) H3O+ + Cl-               (b) H3O+ + OH-

(c) Cl- + OH-                   (d) Unionized HCl 

30. Determine the accurate illustration of the reaction that takes place during the chloralkali process.

(a) NaOH(l) + Cl2 (g) + H2 = 2NaCl(l) + 2H2O(l) + 2NaOH(l) (g)

(b) NaOH(aq) + Cl2 (g) + H2 = (b) 2NaCl(aq) + 2H2O(aq) (g)

(c )NaOH(aq) + Cl2(aq) + H2 = 2NaCl(aq) + 2H2O(l) (aq)

(d) NaOH (aq) + Cl2 (g) + H2 = 2NaCl (aq) + 2H2O (l) (g)

31. Match the acids given in Column (A) with their correct source 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

32. Match the important chemicals given in Column (A) with the chemical formulae given in Column (B)

Column (A)                                                                          Column (B)

(a) Plaster of Paris                                                                (i) Ca(OH)2

(b) Gypsum                                                                             (ii) CaSO4. ½ H2O

(c) Bleaching Powder                                                            (iii)CaSO4.2H2O

(d) Slaked Lime                                                                                   (iv) CaOCl2

33. What effects would the following compounds have on litmus paper? Lemon juice, carbonated soft drink, curd, and soap solution. Moistened NH3 gas.

34. Identify the acid found in ant stings and provide its chemical formula in number. Moreover, describe how to relieve the suffering brought on by ant stings.

35. What happens to eggshell when nitric acid is added?

36. A student created acid and base solutions in two different beakers. She neglected to name the liquids, and the lab is devoid of litmus paper. How will she tell one solution from the other when they are both colourless?

37. If you had to heat up baking powder and washing soda, how would you tell them apart?

38. When salt A, a typical ingredient in baked goods, is heated, it transforms into salt B, which is used to remove water hardness, and gas C is released. When lime water is exposed to gas C, it turns milky. Name A, B, and C.

39. As a byproduct of one of the industrial procedures used to create sodium hydroxide, a gas X is created. The chemical industry uses the compound Y, which is produced by the reaction of the gas X with lime water, as a bleaching agent. Provide the chemical equation for the relevant reactions while identifying X and Y.

40. Fill in the missing data in the following table

                                                                        Salted Obtained from

Name of the Salt                     Formula                                    Base                                  Acid

Ammonium chloride             NH4Cl                                NH4OH                                        –

Copper sulphate          –                      –                                                     -                                         H2 SO4

Sodium chloride                                 NaCl                                    NaOH                                         -                                                                                              

Magnesium nitrate           Mg (NO3 ) 2                                     –                                         HNO3                       

Potassium sulphate             K2 SO4                                       –                                               -                                        

Calcium nitrate                               Ca(NO3 ) 2                                                    Ca(OH)2                                 

41. What do "strong" and "weak" acids mean? Separate the strong acids from the weak acids in the following list of acids. acid mixtures that include sulfuric, formic, citric, acetic, nitric, and hydrochloric acids.

42. A gas that is used in the hydrogenation of oil is produced when zinc metal is treated with a diluted solution of a strong acid. Name the evolved petrol. Provide a test to identify the petrol generated in addition to the chemical equation for the process.

43. In the following schematic diagram for the preparation of hydrogen gas, as shown in Figure 2.3, what would happen if the following changes are made?

(a) The test tube is filled with the same amount of zinc dust instead of zinc granules.

(b) Diluted hydrochloric acid is used in place of diluted sulfuric acid.

(c) Copper turnings are used in place of zinc.

(d) The tube is heated and sodium hydroxide is added in place of the diluted sulfuric acid.

44 . Baking powder is used to make a cake. If your mother makes cake at home without using baking powder,

(A) How and why would it alter the cake's flavour?

(B) What is the process for turning baking soda into baking powder?

(c )What function does the tartaric acid added to baking soda serve in ?

45. When a metal carbonate X reacts with acid, a gas is produced that, after passing through a solution Y, releases the carbonate once more. On the other hand, when dry Y is passed over a gas G produced at the anode during the electrolysis of brine, a chemical Z is produced that is utilised to sanitise drinking water. You are X, Y, G, and Z.

46. When left out in the open, a dry pellet of the common base B collects moisture and becomes sticky. The substance is a leftover from the chloralkali process. Determine B. What kind of reaction takes place when an acidic oxide is applied to B? For one of these solutions, create a balanced chemical equation.

47. A sulphate salt is a white, malleable substance that belongs to Group 2 of the Periodic Table and may be moulded into various shapes using its dough. When this substance is exposed to the elements for a while, it solidifies and cannot be utilised to make moulds. What is the sulphate salt, and why is it acting in this way? Describe the resulting reaction.

48 . Based on the reactions listed below, name the chemical X. Include A, B, and C's names and chemical formulas as well.