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

Which of the following is called milk of magnesia?

  1. Suspension of ${\rm{Mg}}{\left( {{\rm{OH}}} \right) _{\rm{2}}}$
  2. Solution of ${\rm{MgS}}{{\rm{O}} _4}$
  3. Suspension of ${\rm{Mg}}$
  4. Solution of ${\rm{Mg}}{\left( {{\rm{HC}}{{\rm{O}} _3}} \right) _2}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Magnesium hydroxide is the inorganic compound with the chemical formula Mg(OH)₂. It occurs in nature as the mineral brucite.

Milk of magnesia contains magnesium, which is a naturally occurring mineral. The human body requires magnesium to help many of its systems function properly, most notably the muscles and the nerves.

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

Product (S) are :

$Mg _2C _3 {\xrightarrow []{D _2O} } \,\, { \xrightarrow[2.H _2O/\bar{O}H]{1.BH _3.THf}} \,\,{\xrightarrow {H _2/Ni} }\,\, \xrightarrow[\Delta]{Conc.H _3PO _4} (S)$

  1. ${\text{H}}\mathop {\text{C}}\limits _{\mathop {\text{D}}\limits^{\text{|}} } = {\text{CH - C}}{{\text{D}} _{\text{3}}}$
  2. ${{\text{H}} _2}\mathop {\text{C}}\limits _{\mathop {\text{D}}\limits^{\text{|}} } - {\text{CH}}\;{\text{ = }}\;{\text{C}}{{\text{D}} _2}\;\;$
  3. ${{\text{H}} _{\text{2}}}{\text{C}}\; = {\text{CH - C}}{{\text{H}} _{\text{3}}}$
  4. ${{\text{H}} _{\text{2}}}{\text{C}} = \mathop {\text{C}}\limits _{\mathop {\text{D}}\limits^{\text{|}} } - {\text{C}}{{\text{H}} _{\text{3}}}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mg2C3 reacts with D2O to form propyne-d4 (CH3-C=CD). Hydroboration-oxidation adds OH and H across the triple bond, followed by reduction and dehydration, leading to the specified product structure.

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.