Chemistry · Science General

Common Chemical Compounds and Reactions

1,197 Questions

Common chemical compounds and reactions questions test your knowledge of everyday chemicals, their formulas, and their interactions. Topics include properties of acids and bases, hard water chemistry, and compounds like baking soda and plaster of paris. This section is essential for general science preparation.

Acids and basesPlaster of parisHard water chemistryCommon chemical formulasEveryday chemical reactions

Common Chemical Compounds and Reactions Questions

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements
$B\xleftarrow[]{200^oC} CaSO _4.2H _2O\xrightarrow[]{120^oC}A$
$\downarrow$ Strongly heated          Gypsum
$C$

A, B and C are respectively :

  1. plaster of paris, dead burnt plaster, calcium sulphide

  2. dead burnt plaster, plaster of paris, lime

  3. plaster of paris, dead burnt plaster, lime

  4. anhydrous calcium sulphate, plater of paris, calcium sulphite
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When calcium sulfate dihydrate is heated to $120^{o} C$, plaster of paris (A) is obtained.
$CaSO _{ 4 }\cdot 2H _{ 2 }O\xrightarrow { 120^o C } CaSO _{ 4 }\cdot \frac { 1 }{ 2 } H _{ 2 }O+\frac { 3 }{ 2 } H _{ 2 }O\ \quad \quad \quad \quad \quad \quad \quad \quad Plaster\quad \quad \quad \quad \quad \ \quad \quad \quad \quad \quad \quad \quad \quad of\ \quad \quad \quad \quad \quad \quad \quad \quad paris\quad  $
When calcium sulfate dihydrate is heated to $200^o C$, anhydrous calcium sulfate is obtained which is known as dead burnt plaster (B).
$CaSO _{ 4 }\cdot 2H _{ 2 }O\xrightarrow { 200^oC } CaSO _{ 4 }+2H _{ 2 }O$
When Dead burnt plaster is strongly heated, lime (C) is obtained.
$CaSO _{ 4 }\xrightarrow { strongly\quad heat } CaO+2SO _{ 3 }$

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

Cement is mixture of 

  1. Aluminate & Zincate of Calcium

  2. Zincate and Silicate of Calcium

  3. Aluminate and Silicate of Calcium

  4. Aluminate of Calcium and Magnesium
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Portland cement is manufactured primarily from limestone and clay, resulting in a complex mixture containing calcium silicates and calcium aluminates, which are responsible for its setting and hardening properties.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

The plaster of paris is hardened by 

  1. Liberating ${\text{C}}{{\text{O}} _2}$

  2. Giving out water

  3. Combining with water
  4. Changing into ${\text{CaC}}{{\text{O}} _3}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Plaster of Paris hardens by reacting with water to form a solid mass of gypsum crystals, a process known as hydration.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

Setting of plaster of paris is :

  1. oxidation with atmospheric oxygen
  2. combination with atmospheric $CO _2$

  3. dehydration

  4. hydration to yield another hydrate
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$CaSO _4.1/2H _2O \xrightarrow[setting]{H _2O} CaSO _4.2H _2O \xleftarrow[hardening]{} CaSO _4.2H _2O$

plaster of paris                       gypsum                                gypsum
                                             orthorhombic                monoclinic dihydrate
                                                 dihydrate

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

The cementation process is:

  1. gel formation

  2. emulsion formation
  3. both of $A$ and $B$

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cementation process is the hardening of cement during the process of construction. The process starts after adding water to the mixture of cement, sand and small stone pieces. In this, a gel type of product is formed which gets thickened and hardened gradually. So cementation is the process of gel formation.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

Portland cement is manufactured by using:

  1. Limestone, clay and sand

  2. Limestone, gypsum and sand

  3. Limestone, gypsum and alumina

  4. Limestone, clay and gypsum
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Portland cement is the most common type of cement general use around the world, used as a basic ingredient of concrete mortar, stucco and most non-speciality grout. It developed from other types of hydraulic lime in England in the mid 19th century and usually originates from limestone. 


It is a fine powder produced by heating materials in a kiln to form what is called clinker, grinding the clinker, and adding small amounts of other materials. Several types of Portland cement are available with the most common being called ordinary Portland cement (OPC) which is grey in colour, but a white Portland cement is also available.

Portland cement is manufactured by using Limestone, clay and gypsum.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

The main constituent of cement is:

  1. $SiO _2$

  2. CaO
  3. $CaSO _4$
  4. $Al _2O _3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hydraulic cement are made up of a mixture of silicates and oxides in the form of silicon dioxide. It is responsible for the mechanical properties of cement.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

Which of the following is/are constituents of cement?

  1. $SiO _2$
  2. $Al _2O _3$
  3. $CaSO _4$

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Portland cement consists essentially of compounds of lime (calcium oxide, $CaO$) mixed with silica (silicon dioxide, $SiO _2$) and alumina (aluminum oxide, $Al _2O _3$). 

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

Plaster of Paris is obtained by heating:

  1. gypsum

  2. limestone

  3. sodium carbonate

  4. calcium sulphate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Plaster of Paris is made by heating the mineral gypsum. When gypsum is heated to about 150°C it losses water and produces the powder of plaster of Paris.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

The common ingredient required for making cement and glass is:

  1. washing soda

  2. baking soda

  3. limestone

  4. potash
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This glass is typically made using a wet batch process where the composition is primarily limestone, soda ash and silica. 

cement is made by heating limestone (calcium carbonate) with other materials (such as clay) to $1450 ^0C$ in a kiln

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

Cement balls formed in its manufacturing is called:

  1. portland cement

  2. limestone

  3. clinkers

  4. alum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the manufacture of Portland cement, clinker occurs as lumps or nodules, usually 3 millimetres (0.12 in) to 25 millimetres (0.98 in) in diameter, produced by sintering (fused together without melting to the point of liquefaction) limestone and alumino-silicate materials such as clay during the cement kiln stage.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

Finely powdered clay and limestone mixed with water is introduced in:

  1. drum mixer

  2. rotary kiln

  3. pan-type granulator

  4. dryer
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A rotary kiln is a pyroprocessing device used to raise materials to a high temperature (calcination) in a continuous process. Materials produced using rotary kilns include cement, lime.

Cement kilns are used for the pyro-processing stage of manufacture of Portland and other types of hydraulic cement, in which calcium carbonate reacts with silica-bearing minerals to form a mixture of calcium silicates.

Multiple choice chemistry the s-block elements (alkali and alkaline earth metals) some important compounds of calcium some important compounds of magnesium and calcium compounds of s block elements

Cement is the mixture of calcium __________ and calcium ___________, with small amount of gypsum salt.

  1. silicate, carbonate

  2. silicate, aluminate

  3. carbonate, oxide

  4. carbonate, aluminate
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
 Compound  Formula  Shorthand form  % by $weight$ 
 Tricalcium aluminate $Ca _3Al _2O _6$  $C _3A$  10 
 Tetracalcium   $Ca _4Al _2Fe _2O _{10}$ $C _4AF$  8 
Belite or dicalcium silicate  $Ca _2SiO _5$  $C _2S$  20 
Alite or tricalcium silicate  $Ca _3SiO _4$  $C _3S$  55 
Sodium oxide  $Na _2O$  $N $
Potassium oxide  $K _2O$  $K $ upto 2 
Gypsum  $CaSO _4.2H _2O$  $CSH _2$  5 

A cement is a binder, a substance used in construction that sets and hardens and can bind other materials together. The most important types of cement are used as a component in the production of mortar in masonry, and of concrete, which is a combination of cement and an aggregate to form a strong building material.