White Vitriol-Introduction, Physical Properties, Preparations, Chemical Properties, Uses, Practice problems, FAQs

You might see that there are a variety of leather products available in the market. These look so fascinating to you while shopping. Ladies and gentlemen are very much attracted to accessories like hand purses, shoes, leather bags and many more.

Wait! Why am I talking about such things? Can you guess? These things are made up of natural substances but they stay for a long time. Is there any miracle? Of course not!! There is a chemical which is used to preserve leathers and make these accessories stay long.

Here we read about that chemical which keeps such leather products durable for a long time. This compound has a variety of uses and it is also commonly known as ‘White Vitriol”. This compound has also been used in body lotions and eye drops and is very commonly used in day-to-day life.

We will study more about white vitriol and its properties and reactions in detail!

TABLE OF CONTENTS

What is White Vitriol?
Physical Properties of White Vitriol
Preparation of White Vitriol
Chemical Properties of White Vitriol
Structure of White Vitriol
Uses of White vitriol
Practice Problems
Frequently asked questions-FAQs

What is White Vitriol?

Zinc sulfate is an inorganic substance and a major compound of zinc. It is a dietary supplement to treat and prevent zinc deficiency in people at high risk. Excessive supplementation may have negative side effects such as nausea, headaches, and fatigue.

The heptahydrate water of crystallization, having the formula ZnSO₄.7H₂O, is the most prevalent type. Historically, it was referred to as "white vitriol." Colourless solids, zinc sulfate and its hydrates are substances.

Physical properties of Zinc Sulfate, ZnSO₄.7H₂O ( White vitriol)

ZnSO₄.7H₂O is a colourless, solid, white anhydrous crystal. A solid that effloresces is ZnSO₄.7H₂O.

Water can dissolve white vitriol. It is water soluble in nature.
Both crystalline and amorphous pellets of white vitriol are present.
These are hygroscopic in nature.
Molecular mass of White vitriol comes out to be 287.6 a.m.u
White vitriol has a melting point of 100 ℃.
The density of white vitriol comes out to be 1.97 g cm^-3

Preparation of White Vitriol:

Zinc is combined with dilute sulfuric acid to make zinc sulfate. Zinc oxide or carbonate can also be dissolved in dilute sulfuric acid to make this.

$Z n (s) + H_{2} S O_{4} (a q) \to Z n S O_{4} (s) + H_{2} (g)$

$Z n O (s) + H_{2} S O_{4} (a q) \to Z n S O_{4} (s) + H_{2} O (a q)$

$Z n C O_{3} (s) + H_{2} S O_{4} (a q) \to Z n S O_{4} (s) + H_{2} O (a q) + C O_{2} (g)$

Colorless crystals of zinc sulfate,ZnSO₄.7H₂O, form when the solution is concentrated and crystallized below 39°C.

Chemical Properties of White Vitriol

The effects of heating include the following modifications.

A white zinc hydroxide precipitate formed when sodium hydroxide is introduced to a zinc sulfate solution. This precipitate dissolves any extra NaOH to generate sodium zincate.

$Z n S O_{4} (s) + 2 N a O H (s) \to Z n (O H)_{2} ↓ (s) + {N a}_{2} S O_{4} (s) Z n (O H)_{2} (s) + 2 N a O H (s) \to N a_{2} Z n O_{2} (s) + 2 H_{2} O (a q)$

When sodium carbonate solution is added to a zinc sulfate solution, basic zinc carbonate precipitates out in a form of white precipitate.

$4 Z n S O_{4} (s) + 4 N a_{2} {C O}_{3} (s) + 3 H_{2} O (a q) \to Z n C O_{3} . 3 Z n (O H)_{2} (s) + 4 N a_{2} {S O}_{4} (s) + 3 C O_{2} (g)$

However, adding sodium bicarbonate solution to zinc sulfate causes the production of regular zinc carbonate.

$Z n S O_{4} (s) + 2 N a H {C O}_{3} (s) \to Z n C O_{3} (s) + N a_{2} {S O}_{4} (s) + H_{2} O (a q) + C O_{2} (g)$

With alkali metal sulfates and (NH₄)₂SO₄, Zinc sulfate produces double sulfates (double salts) like K₂SO₄.ZnSO₄.6H₂O.

Structure of White Vitriol

One zinc ion can be found in the structure of the white vitriol molecule. The strong electrostatic attraction between zinc and sulfate ions pulls this zinc ion toward them. Seven water molecules can be found in the molecule of white vitriol. Coordinate bonds assist certain water molecules to stick to the zinc ion, whereas hydrogen bonds help other water molecules stick to the zinc ion.

Below is the structural representation of Zinc Sulfate

Uses of White Vitriol:

A dilute zinc sulfate solution is used as an eye lotion.
It is used to create the white paint and pigments known as lithopone (ZnS+BaSO₄).
It serves as a mordant in dyeing and calico printing.
Zinc sulfate solutions are used for both electrolytic refinement and zinc plating.
Starting with zinc sulfate, other zinc compounds like sodium zincate and zinc sulfide can be created.
It serves as a leather preservative.
Acne can be treated with it.
If you have a stomach ache, you can take zinc sulfate with food.

Practice Problems

1. White vitriol ZnSO₄.7H₂O has a percentage weight of Zn that is almost equivalent to

A. 20.35%
B. 22.65%
C. 32.55%
D. 53.25%

Answer: B)
The Molecular weight of White Vitriol , ZnSO₄.7H₂O comes out to be 287 amu.

Let us calculate this,

Molecular weight of Zn is almost equal to 65 amu, Molecular weight of S is almost equal to 32 amu, Molecular weight of oxygen is 16 amu, Molecular weight of hydrogen is almost equal to 1 amu.

Using the above information we can calculate the molecular mass of ZnSO₄.7H₂O

65amu+32amu+(416amu)+7(21amu+16amu)=287 amu

Zn content in white vitriol is 65 amu.

% weight of Zn in White Vitriol can be calculated as,

$% w e i g h t o f Z n = \frac{W e i g h t o f Z n}{M o l e c u l a r w e i g h t o f W h i t e V i t r i o l} \times 100$

$% w e i g h t o f Z n = \frac{65 a m u}{287 a m u} \times 100$

$= 22.65 %$

Hence, B is the correct option.

2. ________________ mixture is also used as white pigment.

A. ZnS+BaSO₄
B. ZnS+MgSO₄
C. Zn(OH)2+BaSO₄
D. Zn(OH)2+MgSO₄

Answer: A)
lithopone is a mixture of ZnS+BaSO₄. It is used to create the white paint and pigments. The following reaction takes place here when heated at 50 to 60 ℃.

$Z n S O_{4} (s) + B a S (s) \to B a S O_{4} ↓ (s) + Z n S ↓ (s)$

3. Thermal decomposition of White vitriol releases ___________.

A. SO₂
B. H₂S
C. SO₂ and H₂S
D. SO₂ and O₂

Answer: D
When heated, white vitriol transforms into zinc oxide and emits sulphur dioxide and oxygen. The decomposition takes place at more than 800 ℃ temperature.

4. A ___________zinc hydroxide precipitate forms when sodium hydroxide is introduced to the zinc sulphate solution.

A. Brown
B. White
C. Yellow
D. Black

Answer: B)
A white zinc hydroxide precipitate formed when sodium hydroxide is introduced to a zinc sulfate solution. Below is the given reaction for this.

$Z n S O_{4} (s) + 2 N a O H (s) \to Z n (O H)_{2} ↓ (s) + {N a}_{2} S O_{4} (s)$

Frequently asked questions-FAQs

1. Is zinc sulfate harmful?
Answer: Inhaling zinc sulfate can irritate the respiratory tract, result in nausea, vomiting, stomach pain, disorientation, mouth depression, a metallic taste, and even result in death. Skin injury from skin contact can result in ulcers, blisters, and scars.

2. What form of zinc supplementation is recommended?
Answer: Zinc picolinate, zinc acetate, and zinc citrate are the best zinc substitutes. The body is able to absorb these three kinds of zinc supplements the easiest. If you want to strengthen your immune system before the cold and flu season hits, it's a good idea to keep a tonne of vitamins on hand.

3. What exactly is called “vitriol” ?
Answer: Sulfate is also known as vitriol. Previously, the sulfate ion was referred to as vitriol. Thus, the name "vitriol" refers to a group of chemical compounds made of the sulfates of various metals, such as copper, zinc, or iron.

Since ancient times, the most prevalent form of this substance has been known. These mineral elements can be distinguished by their colors, such as blue vitriol for hydrated copper(II) sulfate and green vitriol for hydrated iron(II) sulfate.

4. What are zinc major sources?
Answer: It is present in soil, plants, and animals. Natural sources, pesticides, or human activities including farming and the manufacture of batteries, animal feed, and metals are all possible sources of zinc. Additionally, zinc is a food ingredient. An inorganic salt called zinc sulfate dissolves in water to produce zinc ions.