Tag: chemistry

Questions Related to chemistry

Which of the following is called milk of magnesia?

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

  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 ${\rm{Mg}}{\left( {{\rm{HC}}{{\rm{O}} _3}} \right) _2}$

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Correct Option: A
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.

Product (S) are :

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

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

  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. ${{\text{H}} _{\text{2}}}{\text{C}} = \mathop {\text{C}}\limits _{\mathop {\text{D}}\limits^{\text{|}} } - {\text{C}}{{\text{H}} _{\text{3}}}$

Show answer
Correct Option: A

Which of the following metals is present in chlorophyll?

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

  1. $Mg$

  2. $Be$

  3. $Ca$

  4. None of above

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Correct Option: A

Magnesium burns in carbon dioxide giving the products. The formula of the products are :

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

  1. MgO,C

  2. Mg,CO

  3. $MgO _{2}$,C

  4. $Mg(OH) _{2} ,O _{2}$

Show answer
Correct Option: A
Explanation:

Reaction:
$2Mg+CO _2\rightarrow 2MgO+C$

When magnesium burns in carbon dioxide, it forms magnesium oxide and carbon as a product.

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

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

  1. have no effect

  2. precipitate Mg metal

  3. precipitate MgO

  4. lead to dissolution of Be metal

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Correct Option: A

Mixture of $MgCl _2$ and MgO is called :

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

  1. Portland cement.

  2. Sorel's cement.

  3. double salt.

  4. None of these.

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Correct Option: B
Explanation:

Mixing solid MgO  with MgCl2  produces Sorrel cement

Epsom salt is:

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

  1. ${ CuSO } _{ 4 }$

  2. ${ CaSO } _{ 4 }$

  3. ${ MgSO } _{ 4 }.7H _2O$

  4. ${ Na } _{ 2 }{ SO } _{ 4 }$

Show answer
Correct Option: C
Explanation:

It is often encountered as the heptahydrate sulfate mineral epsomite commonly called Epsom salt${ MgSO } _{ 4 }\cdot { 7H } _{ 2 }O$. It has enormous health benefits.

Name a compound which hardens on wetting with water.

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

  1. Calcium sulphate decahydrates

  2. Calcium sulphur hemihydrates

  3. Calcium sulphate

  4. Hydrated calcium sulphate

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Correct Option: B
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 $CaSO _4.1/2H _2O$

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.

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

  1. True

  2. False

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Correct Option: A
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.

The weight of magnesium increases on burning.

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

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Burning of magnesium, it combines with atmospheric oxygen to produce $MgO$. Thus mass gets increased on combustion.

$Mg +O _2$ $\rightarrow$ $MgO\ +$ light and heat