12 Class Fsc Part 2 Short Questions Online Preparation for Chemistry chapter 2 (S-Block elements)

Question # 1

What is cement plaster and Hard finish plaster?

Ans 1: Cement Plaster:It is Plaster of Pairs to which usually glue or other oils have been added as retarders to prolong the time of setting.
Ans 2: Hard finish plaster:These are made by the calcination of anhydrous sulphate with alum or borax.These plaster are set very slowly but give a hard finish.

Question # 2

What is mil;k of Magnesia and for which treatment it used.

Ans 1: A suspension of Mg(OH)₂in water is called milk of magnesia and it is used for the treatment of acidity in stomach.

Question # 3

Complete the reactions: i)Mg₃N₂+ H₂O---->? ii) KO₂+ CO₂--->?

Ans 1: i) Mg₃N₂+ 6H₂O--->2NH₃+ 3Mg(OH)₂
ii) 4KO₂+ 2CO₂---->2kO₂+ 2CO₂---->2K₂CO₃+3O₂

Question # 4

Give advantages of Down's cell.

Ans 1: i) Metallic fog is not produced.
ii) Liquid sodium can easily be collected at 600^oC.
iii) Material of cell is not attacked by the products formed during the electrolysis.

Question # 5

What happens when: 1) Li₂CO₃ 2) Na₂CO₃is heated.

Ans 1: Lithium has low electropositive character,thus its carbonate are not so stable and therefore decomposed giving lithium oxide on heating.
Li₂CO₃----------------->Li₂O + CO₂
Ans 2: At temperature below 35.2 ^oC,Na₂CO₃crystallizes out from water as Na₂CO₃.10H₂O which is called washing soda.Above this temperature it crystallizes as Na₂CO₃.H₂O. On standing in air,Na₂CO₃.10H₂O slowly loses.

Question # 6

What are main uses of Plaster of Paris?

Ans 1: 1) Plaster of Paris is used for making plaster walls,casts of statuary,coins,etc.
2) It is used in surgery,Plaster of Paris bandages are used for holding in Place fractured bones after they have been set.
3) It is also used in cement Plaster in which usually glue or other oils have been added as retarders to prolong the time of setting.

Question # 7

How Plaster of Paris is formed.Give its two uses?

Ans 1: Formation of Plaster of Paris:When gypsum is heated under carefully controlled conditions.it loses three quarters of its water of crystallization,the resulting product is called Plaster of Paris.Calcium sulphate occurs in nature as gypsum CaSO₄.2H₂O.When it is heated above 100^oC,it loses three quarters of its water of crystallization,giving a white powder which is known as Plaster of Paris.
2CaSO₄.2H₂O------------->(CaSO₄)₂.H₂O+3H₂O
Gypsum Plaster of Paris
Ans 2: Uses of Plaster of Paris:Plaster of Paris is used for making plaster walls,casts of statuary,coins,etc.
It is used in surgery,Plaster in which usually glue or other oils have been added as retarders to prolong the time of setting.

Question # 8

Give reactions of BeO with a) NaOH b) H₂SO₄.

Ans 1: a) Reactions of BeO with NaOH:BeO + 2NaOH------>Na₂BeO₂+ H₂O
b) Reactions of BeO with H₂SO₄:BeO + H₂SO₄--------->BeSO₄+ H₂O

Question # 9

Give two uses of Lime in industry.

Ans 1: i) Large quantities of lime are used in the extraction and refining of metals.
ii) Lime is used in paper,cement and leather industries.

Question # 10

Which Elements are called as alkaline earth metals?Why this name is used for these elements?

Ans 1: Elements of group IIAare called alkaline earth metals.The alkaline earth metals are beryllium,magnesium,calcium,strontium,barium and radium.They are called alkaline earth metals because they produce alkalies in water and are widely distributed in earth crusts.

Latest Educational News Stories

Pakistan's Largest Database of Colleges and Universities

BS Programs

University Past Papers

University Results

Exam Results 2024

Study Abroad Programs and Opportunities for Pakistani Students

12 Class Fsc Part 2 Short Questions Online Preparation for Chemistry chapter wise

Online Short Questions For Chapter 2 "12th Class Chemistry Chapter 2 Short Questions Preparation "

Chemistry - 12th Class Chemistry Chapter 2 Short Questions Preparation

What is cement plaster and Hard finish plaster?

What is mil;k of Magnesia and for which treatment it used.

Complete the reactions: i)Mg3N2+ H2O---->? ii) KO2+ CO2--->?

Give advantages of Down's cell.

What happens when: 1) Li2CO3 2) Na2CO3is heated.

What are main uses of Plaster of Paris?

How Plaster of Paris is formed.Give its two uses?

Give reactions of BeO with a) NaOH b) H2SO4.

Give two uses of Lime in industry.

Which Elements are called as alkaline earth metals?Why this name is used for these elements?

Prepare Complete Set Wise Questions For Chapter 2 "12th Class Chemistry Chapter 2 Short Questions Preparation "

Set 1

Set 2

Set 3

Set 4

12th Class Chemistry Chapter 2 Short Questions Preparation - Set 1

What is cement plaster and Hard finish plaster?

What is mil;k of Magnesia and for which treatment it used.

Complete the reactions: i)Mg3N2+ H2O---->? ii) KO2+ CO2--->?

Give advantages of Down's cell.

What happens when: 1) Li2CO3 2) Na2CO3is heated.

What are main uses of Plaster of Paris?

How Plaster of Paris is formed.Give its two uses?

Give reactions of BeO with a) NaOH b) H2SO4.

Give two uses of Lime in industry.

Which Elements are called as alkaline earth metals?Why this name is used for these elements?

12th Class Chemistry Chapter 2 Short Questions Preparation - Set 2

What is the action of litmus with aqueous solution of Na2CO3?

Write points to show peculiar behavior of Berylium.

Write a brief note on the occurrence of alkaline earth metals?

Why aqueous solution of Na2Co3is alkaline in nature?

How Portland cement is made?Why Gypsum is added in the cements?

How Gypsum is converted into Plaster of Paris?

Why lime water turns milky CO2but becomes clear with excess CO2?

How potassium superoxide KO2has very interesting use in breathing equipment for mountains and space crafts?

Why S-block elements are called as alkali metals and alkaline earth metals?

How Plaster of Paris is formed.Give its two uses?

12th Class Chemistry Chapter 2 Short Questions Preparation - Set 3

Write the formulae of 1) Natron 2) Dolomite.

Why lime water turns milky CO2but becomes clear with excess CO2?

What is the action of litmus with aqueous solution of Na2CO3?

Complete the reactions: i)Mg3N2+ H2O---->? ii) KO2+ CO2--->?

Why is CaCl2added in molten Nacl in Down's cell?

Why Calcium is essential for the normal growth of plants?

How Plaster of Paris is formed.Give its two uses?

How Gypsum is converted into Plaster of Paris?

What are main uses of Plaster of Paris?

Give two uses of Lime in industry.

12th Class Chemistry Chapter 2 Short Questions Preparation - Set 4

Give advantages of Down's cell.

Write points to show peculiar behavior of Berylium.

What is the function of calcium in plant growth.

What is cement plaster and Hard finish plaster?

Complete the reactions: i)Mg3N2+ H2O---->? ii) KO2+ CO2--->?

Lithium is least reactive element of all alkali metals.

How Portland cement is made?Why Gypsum is added in the cements?

When sodium reacts with water,hydrogen which evolves catches fire,Why?

Why group II-A elements are called Alkaline Earth Metals.

How chlorine produced in Diaphragm cell,is protected to react with Hydroxide ions?

12th Class Chemistry Chapter 2 Preparation

Is this page helpful?

Share your comments & questions here

Complete the reactions: i)Mg₃N₂+ H₂O---->? ii) KO₂+ CO₂--->?

What happens when: 1) Li₂CO₃ 2) Na₂CO₃is heated.

Give reactions of BeO with a) NaOH b) H₂SO₄.

Complete the reactions: i)Mg₃N₂+ H₂O---->? ii) KO₂+ CO₂--->?

What happens when: 1) Li₂CO₃ 2) Na₂CO₃is heated.

Give reactions of BeO with a) NaOH b) H₂SO₄.

What is the action of litmus with aqueous solution of Na₂CO₃?

Why aqueous solution of Na₂Co₃is alkaline in nature?

Why lime water turns milky CO₂but becomes clear with excess CO₂?

How potassium superoxide KO₂has very interesting use in breathing equipment for mountains and space crafts?

Why lime water turns milky CO₂but becomes clear with excess CO₂?

What is the action of litmus with aqueous solution of Na₂CO₃?

Complete the reactions: i)Mg₃N₂+ H₂O---->? ii) KO₂+ CO₂--->?

Why is CaCl₂added in molten Nacl in Down's cell?

Complete the reactions: i)Mg₃N₂+ H₂O---->? ii) KO₂+ CO₂--->?