BITSAT Chemistry The S Block Elements MCQs

Question: Dead burn plaster is

a) CaSO₄.2H₂O

b) MgSO₄. 7H₂O

c) CaSO₄.½ H₂O

d) CaSO₄

Answer: CaSO₄

Question: Which of the following is not present in Portland cement?

a) Ca₂SiO₄

b) Ca₃SiO₅

c) Ca₃(PO₄)₂

d) Ca₃Al₂O₆

Answer: Ca₃(PO₄)₂

Question: Lithophone is :

a) ZnSO₄ + PbS

b) BaSO₄ + ZnS

c) PbO₂

d) ZnSO₄

Answer: BaSO₄ + ZnS

Question: Which of the following among alkali metal is most reactive ?

a) Na

b) K

c) Rb

d) Cs

Answer: Cs

Question: The alkali metals form salt-like hydrides by the direct synthesis at elevated temperature. The thermal stability of these hydrides decreases in which of the following orders ?

a) CsH > RbH > KH > NaH > LiH

b) KH > NaH > LiH > CsH > RbH

c) NaH > LiH > KH > RbH > CsH

d) LiH > NaH > KH > RbH > CsH

Answer: LiH > NaH > KH > RbH > CsH

Question: Which of the following has correct increasing basic strength?

a) MgO < BeO < CaO < BaO

b) BeO < MgO < CaO < BaO

c) BaO < CaO < MgO < BeO

d) CaO < BaO < BeO < MgO

Answer: BeO < MgO < CaO < BaO

Question: When a crystal of caustic soda is exposed to air, a liquid layer is deposited because :

a) Crystal loses water

b) Crystal absorbs moisture and CO₂

c) Crystal melts

d) Crystal sublimes

Answer: Crystal absorbs moisture and CO₂

Question: Sodium peroxide in contact with most air turns white due to formation of :

a) Na₂CO₃

b) Na₂O

c) NaOH

d) NaHCO₃

Answer: NaOH

Question: The value of x is maximum for

a) MgSO₄.x H₂O

b) CaSO₄.x H₂O

c) BaSO₄.x H₂O

d) All have the same value of x.

Answer: MgSO₄.x H₂O

Question: Portland cement does not contain

a) CaSiO₄

b) Ca₂SiO₅

c) Ca₂Al₂O₆

d) Ca₃(PO₄)₂

Answer: Ca₃(PO₄)₂

Question: In curing cement plasters water is sprinkled from time to time. This helps in

a) Developing interlocking needle-like crystals of hydrated silicates

b) Hydrating sand and gravel mixed with cement

c) Converting sand into silicic acid

d) Keeping it cool

Answer: Developing interlocking needle-like crystals of hydrated silicates

Question: LiAlH₄ is used as :

a) An oxidizing agent

b) A reducing agent

c) A mordant

d) A water softener

Answer: A reducing agent

Question: Which of the following among alkali metal is most reactive ?

a) Na

b) K

c) Rb

d) Cs

Answer: Cs

Question: When a crystal of caustic soda is exposed to air, a liquid layer is deposited because :

a) Crystal loses water

b) Crystal absorbs moisture and CO₂

c) Crystal melts

d) Crystal sublimes

Answer: Crystal absorbs moisture and CO₂

Question: In curing cement plasters water is sprinkled from time to time. This helps in

a) Developing interlocking needle-like crystals of hydrated silicates

b) Hydrating sand and gravel mixed with cement

c) Converting sand into silicic acid

d) keeping it cool

Answer: Developing interlocking needle-like crystals of hydrated silicates