Tag: salts and their properties

Questions Related to salts and their properties

Which of the following is used in the manufacture of gun powder?

  1. Chile saltpetre

  2. Nitre

  3. Both A and B

  4. None of the above


Correct Option: C
Explanation:

Chile saltpetre(Sodium nitrate), is a deliquescent crystalline sodium salt. Nitre is potassium nitrate. They are used in the manufacture of gun powder, nitric acid etc. It is a mixture of sulfur, charcoal, and potassium nitrate (saltpeter).

Common salt besides being used in kitchen can also be used as the raw material for making:
(i) washing soda
(ii) bleaching powder
(iii) baking soda
(iv) slaked lime

  1. (i) and (ii)

  2. (i), (ii) and (iv)

  3. (i) and (iii)

  4. (i), (iii) and (iv)


Correct Option: C
Explanation:

A. Baking soda is sodium hydrogen carbonate which is prepared by Solvay process which is the reaction of sodium chloride,ammonia and carbon dioxide in water. The calcium carbonate is used in the reaction to get carbon dioxide gas.
${ CaCO } _{ 3 }\rightarrow CaO+{ CO } _{ 2 }\ { 2NH } _{ 3 }+{ CO } _{ 2 }+{ H } _{ 2 }O\rightarrow \left( { NH } _{ 4 } \right) _{ 2 }{ CO } _{ 3 }+{ CO } _{ 2 }+{ H } _{ 2 }O\rightarrow { NH } _{ 4 }{ HCO } _{ 3 }\ { NH } _{ 4 }{ HCO } _{ 3 }+NaCl\rightarrow { NaHCO } _{ 3 }+{ NH } _{ 4 }Cl$
B. Washing soda is sodium carbonate which is prepared from the sodium chloride.
$2NaCl+{ CaCO } _{ 3 }\rightarrow { Na } _{ 2 }{ CO } _{ 3 }+Ca{ Cl } _{ 2 }$

 Column A  Column B
 A. Bleaching powder  i. Preparation of glass
 B. Baking soda  ii. Production of $H _2$ and $Cl _2$
 C. Washing soda  iii. Decolourisation
 D. Sodium chloride  iv. Antacid

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

  1. A(ii), B(i), C(iv), D(iii)

  2. A(iii), B(ii), C(iv), D(i)

  3. A(iii), B(iv), C(i), D(ii)

  4. A(ii), B(iv), C(i), D(iii)


Correct Option: C
Explanation:

A. Bleaching powder is calcium hypochlorite
${ 2CaOCl } _{ 2 }+{ H } _{ 2 }{ SO } _{ 4 }\rightarrow { CaCl } _{ 2 }+{ CaSO } _{ 4 }+2HClO\ HClO\rightarrow HCl+\left[ O \right] \xrightarrow { Coloured\quad matter } Colourless\quad product$
B. Baking soda is sodium bicarbonate which is basic in nature and used as an antacid.
${ NaHCO } _{ 3 }$
C. Sodium carbonate which has a common name washing soda, a monohydrate which is used in the preparation of glass. It is used to flux silica by lowering down the temperature.
Two forms of sodium carbonate are used i.e heavy and light. The light form is obtained first and is converted to heavy form. The heavy form is is used as a solid in making glass where it is used as flux in the melting of silica.${ Na } _{ 2 }{ CO } _{ 3 }\cdot { H } _{ 2 }O$
D. The electrolysis of aqueous solution of sodium chloride gives hydrogen at the cathode and chlorine at the anode. This solution is called as the brine solution. It helps in the evolution of hydrogen gas and chloride gas.

State True or False.
Decomposition of calcium phosphate present in bone ash with concentrated sulphuric acid produces phosphoric acid.
  1. True

  2. False


Correct Option: A
Explanation:

Bone ash is Tricalcium phosphate in the form of hydroxyapatite ${ Ca } _{ 5 }\left( OH \right) { \left( P{ O } _{ 4 } \right)  } _{ 3 }$. Phosphoric acid is obtained from hydroxyapatite when treated with sulphuric acid.
$2{ Ca } _{ 5 }{ \left( P{ O } _{ 4 } \right)  } _{ 3 }OH+10{ H } _{ 2 }S{ O } _{ 4 }+18{ H } _{ 2 }O\longrightarrow 6{ H } _{ 3 }P{ O } _{ 4 }+10CaS{ O } _{ 4 }.2{ H } _{ 2 }O$

Match the compounds /metal in $(X)$ with their uses in $(Y)$.

$X$ $Y$
$A.$ Liquid sodium metal $I.$ Breathing apparatus in submarine
$B.$ Potassium stearate $II.$ Explosive
$C.$ Potassium nitrate $III.$ Coolant in nuclear reaction
$D.$ Potassium superoxide $IV.$ Soft soap
  1. $A-I\, \quad\, B-III\, \quad\, C- II\, \quad\, D- IV$

  2. $A-III\, \quad\,B-  IV\, \quad\,C-  II\, \quad\, D- I$

  3. $A- II\, \quad\,B- I\, \quad\, C- III\, \quad\, D- IV$

  4. $A- IV\, \quad\, B- II\, \quad\, C- III\, \quad\,D-  I$


Correct Option: B
Explanation:

1. Liquid sodium metal is used as coolant in nuclear reaction
2. 
Potassium stearate is used in soft soap
3. 
Potassium nitrate is explosive
4.
 Potassium superoxide, which gives off oxygen as it absorbs carbon dioxide is used in Breathing apparatus in submarine

The uses of bleaching powder are:

  1. it is used for bleaching cotton

  2. it is used as an oxidizing agent in chemical industries

  3. it can be used for disinfecting water

  4. all of the above


Correct Option: D
Explanation:

Bleaching powder $(CaOCl _2)$ has many uses and some of them are as follows :-

1.It is used in bleaching dirty clothes in launder, as a bleaching agent in cotton and linen in the textile industry.
2.Due to evolution of nascent oxygen, it is used as an oxidizing agent in the chemical industries.
3.It can be used as a disinfectant which can be used for disinfecting water to make it potable.
Hence, the correct answer is option (D).

The salt we use in our food is:

  1. $NaCl$

  2. $CaCl _2$

  3. $KCl$

  4. $MgCl _2$


Correct Option: A
Explanation:

Sodium chloride$(NaCl)$, also known as common salt is used in food. It is obtained by evaporation of sea water.

However other salts like $MgCl _2,CaCl _2,KCl$ are used in replacement therapy and given when their amount in the body goes down.
Hence, the correct answer is option (A).

When picric acid is treated with aqueous sodium bicarbonate $ \left( \mathrm { NaH }  ^{ 14 } \mathrm { CO } _ { 3 } \right) $, a gas is liberated with effervescence. The gas evolved would be

  1. $ H _ { 2 } $

  2. $ \mathrm { CO } _ { 2 } $

  3. $ ^ { 14 } \mathrm { CO } _ { 2 } $

  4. $ \mathrm { NO } _ { 2 } $


Correct Option: B

Effervescence is seen when a bottle of soda water is opened.

  1. True

  2. False


Correct Option: A
Explanation:

The liquid in the soda bottle is under high pressure. When you open the bottle, the dissolved carbon dioxide is depressurized and wants to rapidly expand. Thus effervescence is seen when a bottle of soda is opened.

Bleaching powder is made up of : 

  1. lime and chlorine

  2. soda ash and chlorine

  3. chlorine and charcoal

  4. none of these


Correct Option: A
Explanation:

Calcium hydroxide on reaction with chlorine produces bleaching powder. 


$Ca(OH) _2+Cl _2\to Ca(OCl)Cl+H _2O$