Tag: the s-block elements

Quizzes (13) Questions (117)

Questions Related to the s-block elements

Multiple choice some important compounds of magnesium and calcium the s-block elements chemistry

Beryllium is placed above magnesium in the group II. Beryllium dust, therefore, when added to $MgCl {2}$ solution will ____________.

  1. have no effect

  2. precipitate Mg metal

  3. precipitate MgO

  4. lead to dissolution of Be metal
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Beryllium is less reactive than magnesium and cannot displace magnesium from its salts. In fact, magnesium is more electropositive than beryllium.

Multiple choice some important compounds of magnesium and calcium the s-block elements chemistry

Name a compound which hardens on wetting with water.

  1. Calcium sulphate decahydrates

  2. Calcium sulphur hemihydrates

  3. Calcium sulphate

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

The calcium compound that hardens on wetting with water is commonly known as Plaster of Paris (POP), chemically known as calcium sulphate hemihydrate having the formula $CaSO _4.1/2H _2O$

Multiple choice some important compounds of magnesium and calcium the s-block elements chemistry

The reaction between marble and dilute $H _2SO _4$ is not used to prepare carbon dioxide for laboratory purpose.
Answer whether the above statement is true or false.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Insoluble $CaSO _4$ is formed which deposits on the surface of marble and prevent the further action of dilute $H _2SO _4$, so the evolution of $CO _ 2$ ceases after some time.

Multiple choice some important compounds of magnesium and calcium the s-block elements chemistry

In paper industry, the chemical compound used for bleaching is :

  1. potassium sulphite

  2. calcium sulphate

  3. sulphuric acid

  4. calcium bisulfite
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A bleaching agent is a material that lightens or whitens a substrate through chemical reaction. The bleaching reactions usually involve oxidative or reductive processes that degrade color systems In paper industry, the chemical compound used for bleaching is calcium bisulphate. 

Multiple choice some important compounds of magnesium and calcium the s-block elements chemistry

How can Calcium Sulphate be produced from $Ca _3(PO _4) _2$ ?

  1. Reacting with Sulphuric acid

  2. Reacting with Sulphur

  3. Reacting with Sulphur trioxide

  4. Reacting with Sulphur dioxide
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When Calcium Phosphate is treated with Sulphuric Acid, Calcium Sulphate is obtained as a precipitate along with the formation of Phosphoric Acid. The balanced equation can be written as-
$Ca _3(PO _4) _2$ $+$ $3H _2SO _4$ $=$ $2H _3PO _4$ $+$ $3CaSO _4$