Tag: chemistry

Questions Related to chemistry

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

  1. potassium sulphite

  2. calcium sulphate

  3. sulphuric acid

  4. calcium bisulfite


Correct Option: D
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. 

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


Correct Option: A
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-
$Ca _3(PO _4) _2$ $+$ $3H _2SO _4$ $=$ $2H _3PO _4$ $+$ $3CaSO _4$

How is ${MgSO} _{4}$ produced from ${MgCO} _{3}$?

  1. ${MgCO} _{3}$${+}$ ${S}$

  2. ${MgCO} _{3}$${+}$ ${SO} _{2}$

  3. ${MgCO} _{3}$${+}$ ${SO} _{3}$

  4. ${MgCO} _{3}$ ${+}$ ${H} _{2}{SO} _{4}$


Correct Option: D
Explanation:

Magnesium Sulphate is produced from Magnesium carbonate by reacting the carbonate with Sulphuric acid. The balanced equation can be written as-
${MgCO} _{3}$${+}$ ${H} _{2}{SO} _{4}$  ${=}$ ${MgSO} _{4}$ ${+}$ ${CO} _{2}$ ${+}$ ${H} _{2}{O}$

What is the chemical formula of Gypsum?

  1. ${CaSO} _{4}$${.}$${5H} _{2}{O}$

  2. ${CaSO} _{4}$${.}$${7H} _{2}{O}$

  3. ${CaSO} _{4}$${.}$${2H} _{2}{O}$

  4. ${CaSO} _{4}$${.}$${9H} _{2}{O}$


Correct Option: C
Explanation:

The chemical formula of Gypsum is ${CaSO} _{4}$${.}$${2H} _{2}{O}$. It contains two moles of water in it. It can also be said as Calcium Sulphate dihydrate.

Calcium Suphate can be produced by :

  1. ${ZnSO} _{4}$ ${+}$ ${CaO}$

  2. $FeSO _4 + CaO + H _2O$

  3. $MgSO _4 + CaSO _4$

  4. Both A and C


Correct Option: D
Explanation:

Gypsum or Calcium sulphate can be produced from Zinc Sulphate by reacting Zinc Sulphate with Calcium Oxide or lime. We get a precipitate of Calcium Sulphate. The reaction can be written as-
${ZnSO} _{4}$ ${+}$ ${CaO}$ ${=}$ ${CaSO} _{4}$ ${+}$ ${ZnO}$

What is the chemical formula of Epsom Salt?

  1. ${MgSO} _{4}$${.}$${2H} _{2}{O}$

  2. ${MgSO} _{4}$${.}$${5H} _{2}{O}$

  3. ${MgSO} _{4}$${.}$${7H} _{2}{O}$

  4. ${MgSO} _{4}$${.}$${9H} _{2}{O}$


Correct Option: C
Explanation:

The chemical formula of Epsom Salt is ${MgSO} _{4}$${.}$${7H} _{2}{O}$. Or it is also known as Magnesium Sulphate heptahydrate.

How is Magnesium sulphate produced from Magnesium?

  1. $Mg$ $+$ $H _2SO _4$

  2. $Mg$ $+$ $SO _2$

  3. $Mg$ $+$ $SO _3$

  4. $Mg$ $+$ $H _2SO _3$


Correct Option: A
Explanation:

When $Mg$ is dissolved in dilute Sulphuric acid, an aqueous solution of Magnesium Sulphate is obtained. The reaction can be represented as-
$Mg$ $+$ $H _2SO _4$ $=$ $MgSO _4$ $+$ $H _2$
This colourless aqueous solution when evaporates, colorless crystals of $MgSO _4.7H _2O$ are formed.

What happens when Epsom salt is heated?

  1. $MgSO _4.H _2O$

  2. $MgSO _4$

  3. $MgO$

  4. $SO _3$


Correct Option: A,B,C,D
Explanation:

When Epsom salt is heated, all the above mentioned products are obtained. When it is heated at $150^o$ C, $MgSO _4.H _2O$ is obtained. When this is further heated at $200^o$ C, $MgSO _4$ is obtained. On further heating $MgO$ and $SO _3$ are obtained.
$MgSO _4.7H _2O$ $+$ $(heat)$ $=$ $MgSO _4.H _2O$  
$MgSO _4.H _2O$ $+$ $(heat)$ $=$ $MgSO _4$
$MgSO _4$ $+$ $(heat)$ $=$ $MgO$ $+$ $SO _3$

What is/are the uses of Epsom salt?

  1. Pharmaceutical use

  2. Agricultural use

  3. used as a brewing salt

  4. Used as a desiccant


Correct Option: A,B,C,D
Explanation:

Epsom salt – actually magnesium sulfate – helps seeds germinate, makes plants grow bushier, produces more flowers, increases chlorophyll production and deters pests, such as slugs and voles. It also provides vital nutrients to supplement your regular fertilizer.

Epsom salt is a popular remedy for many ailments.

People use it to ease health problems, such as muscle soreness and stress. It's also affordable, easy to use, and harmless when used appropriately

Epsom is used to add sulfate and magnesium ions to brewing water.

Drie-Rite is a brand of Anhydrous Calcium Sulfate commonly used as a Desiccant.

Epsom salt has all the above mentioned uses.

What are the water molecules attached to Epsom salt called?

  1. Water of evaporation

  2. Water of condensation

  3. Water of hydration

  4. None of these


Correct Option: C
Explanation:

The seven molecules of water attached to $MgSO _4.7H _2O$ are known as water of hydration. By definition, it is the amount of water attached to a compound to form a hydrate. Epsom salt is also known as Magnesium sulphate heptahydrate.