Acids, bases and salts Worksheet-5

Acids, bases and salt Worksheet-5

 

Multiple Choice Questions:

  1. Magnesium sulphate is

(A) Salt of strong acid and weak base

(B) Salt of strong base and weak acid

(C) Salt of strong acid and strong base

(D) Salt of weak acid and weak base

 

  1. Which acid cannot be stored in glass bottle?

(A) HNO3             (B) HCl(conc)     (C) H2SO4

(D) HCl(conc)       (E) HF

 

  1. What is pH of blood ?

(A) 2                     (B) 7                     (C) 6                     (D) 7.4

 

  1. Which solution will be more acidic 1M HCl or 1M CH3COOH.

(A) 1M HCl

(B) 1M CH3COOH

(C) Both of them will have same Ph

(D) None of these

 

  1. Name the acid and base used to prepare-NaHCO3

(A) NaOH, H2CO2                             (B) NaH, H2CO3

(C) H2CO3, NaOH                              (D) All of these

 

  1. Assertion-Washing soda crystals become moist when exposed to air.

Reason-Washing soda reacts with moisture forming sodium hydroxide.

(A) Both assertion and reason are correct

(B) Assertion is correct but reason is wrong

(C) Assertion is wrong but reason is correct

(D) Both assertion and reason are wrong.

 

  1. What are the products of CH3COOH(aq)

(A) CH3COO + H+                        (B) H+ + OH

(C) Both a and b                              (D) CH3CO + H+

 

  1. Curd and other sour food-stuffs should not be kept in copper vessels because

(A) They are basic in nature and react with copper evolving Hydrogen gas.

(B) They contain acids which can react with copper metal of vessel forming poisonous metal compound.

(C) Water present in the food reacts with copper forming copper hydroxide.

(D) The given statement is wrong they can be kept in copper vessels

 

  1. What are the products formed when metal oxides are treated with acids?

(A) Metal salt + water                     (B) Metal salt + H2 gas

(C) Metal salt + CO2(g)                   (D) Metal salt + O2 gas

 

  1. What happens when carbon dioxide is passed through lime water for as short time?

(A) Lime water turns milky due to the formation of calcium carbonate(s)

(B) White ppt of calcium carbonate dissolves due to the formation of calcium hydrogen carbonate.

(C) Carbon di-oxide reacts with calcium hydroxide forming calcium oxide which makes lime water milky.

(D) None of these

 

  1. Equal amounts of zinc granules are taken in test tubes. (A) and (B). Hydrochloric acid is added to test tube (A) while citric acid is added to test tube (B). In which test tube fizzing will occur more vigorously?

(A) (A)

(B) (B)

(C) Fizzing will be same in both the test tubes.

(D) All of these

 

  1. What are the products formed in the given reaction-

(A) Ca(SO4)2 + H2O                           (B) CaSO4 + H2O + H+(aq)

(C) CaSO4 + H2O + OH(aq)             (D) CaSO4 + 2H2O

 

  1. Tooth paste is acidic , or alkaline, or Neutral-

(A) Alkaline as it increases the pH of mouth and protects teeth.

(B) Acidic as it lowers the pH of the mouth thus destroying microorganisms in mouth which causes tooth decay.

(C) Neutral as change in pH of the mouth will cause damage to the tissues.

(D) None of these

 

  1. Solution of sodium carbonate in water is

          (A) acidic             (B) basic               (C) Neutral          (D) Strong base

 

  1. During electrolysis of brine Hydrogen gas is produced at–

(A) Anode

(B) Cathode

(C) Both anode and cathode in small amounts

(D) Both A and C

 

  1. What are the products formed when sodium bicarbonate is heated?

(A) Sodium carbonate, carbon dioxide and water

(B) Sodium oxide, carbon di-oxide and water.

(C) sodium hydroxide and water

(D) None of these.

 

  1. Baking powder is composed of-

(A) sodium hydrogen carbonate

(B) sodium hydrogen carbonate + tartaric acid

(C) sodium hydrogen carbonate + acetic acid

(D) Sodium hydrogen, carbonate + citric acid.

 

  1. What are the products formed in the given reaction-

(A) NaCl + H2C3                                (B) N2CO3 + 2HCl

(C) NaCl + H2O + CO2                          (D) NaCl + H2O + CO

 

Answer key:

  1. (C)

Copper sulphate is the salt of copper hydroxide and sulphuric acid.

  1. (E)

Hydrofluoric acid cannot be stored in glass bottles. Glass is made of sodium silicate (Na­2SiO3). silicate bond can only be cleaved by Hydro fluoric acid

  1. (D)
  2. (A)

Hydrochloric acid is a strong acid where as acetic acid is a weak acid.

H+ concentration insolution is less

  1. (C)
  2. (B)

When exposed to air washing soda (Na3CO3) absorbs water forming Na2CO3.10 H2O.10 H2O

  1. (C)
  2. (B)
  3. (A)
  4. (A)
  5. (A)

Hydrochloric acid is a mineral acid and citric acid is an organic acid. Mineral acids are stronger than organic acids. The amount of H+ ions produced is more in test tube (A)

  1. (D)
  2. (A)
  3. (D)

Na2CO3 → 2Na+ + CO32–The solution is strongly basic due to the formation of sodium hydroxide. H2O → H+ + OH

  1. (B)
  2. (A)
  3. (B)

Baking powder contains sodium hydrogen carbonate and tartaric acid. If only NaHCO3 is taken, on heating NaHCO3 will form Na2CO3 which will give bitter taste to Bakery products. So tartaric acid is mixed. Na2CO3 formed reacts with tartaric acid and is neutralized and gives a pleasant taste

  1. (C)

Metal carbonates react with acids forming their salts, water and carbon di-oxide gas.