Question

physical properties of dihydrogen​

Answer 1

One common way to prepare dihydrogen gas in the lab is by reacting Zinc with a diluted acid. It results in Zinc forming Zinc Sulphate (or zinc chloride) and releasing hydrogen in a gas form

Zn + H2SO4 → ZnSO4 + H2

Zn +HCl → ZnCl2 + H2

Reacting Zinc with Alkaline

Zinc can also react with an aqueous alkali such as Sodium Hydroxide, The sodium and zinc will combine and give us dihydrogen as another product. The reaction is as follows

Zn + 2NaOH → Na2ZnO2 + H2

Commercial Preparation of Dihydrogen

The commercial preparation of hydrogen is a huge industry because there is a huge demand for hydrogen in the production of fertilizers and oil-refining process.

Electrolysis of Water

The method helps in the production of a very pure form of hydrogen from water. Electricity passes through the water breaking up the water molecule. The hydrogen collects at the cathode while oxygen collects at the anode.

Lane’s Process

Here Water Gas (a mixture of carbon monoxide and hydrogen) and steam are alternatively passed over iron at very high temperatures of up to 800 C. The iron is first oxidized releasing hydrogen and has to replaced with fresh metal. Then the iron reduces with water gas back to a metal. The reactions are as follows

3Fe + 4H2O → Fe3O4 + 4H2

Fe3O4 + 4CO → 3Fe + 4CO2

Net reaction is

CO + H2O → CO2 + H2

From Natural Gas

This remains the cheapest way to produce hydrogen on a commercial scale. The gas is heated to high temperatures (up to 1100 C) with steam and a Nickel catalyst. This results in the methane molecules breaking into Carbon Monoxide and Hydrogen.

CH4 + H2O→ CO + 3H2

Properties of Dihydrogen

Physical Properties of Dihydrogen

At room temperature, this diatomic molecule of hydrogen is found in a gaseous state

It is an absolutely colorless, odorless and tasteless gas which makes it very hard to detect

It is the lightest element of our periodic table. Has the molecular weight f 1.00794

It also has the lowest density of all elements

It is highly combustible or inflammable. On combustion it produces water. Also, it burns with a blue flame.

It liquefies at very low temperatures of nearly -250 C

Chemical Properties of Dihydrogen

Hydrogen is represented by its symbol ‘H’. However, in nature, it occurs in its diatomic form as ‘H2‘ known as Dihydrogen

Hydrogen has no effect on litmus paper, i.e. it is neutral (neither acidic nor alkaline)

Dihydrogen is a non-metal

It is fairly non-reactive in nature. Since dihydrogen is a stable molecule it is not very reactive

Dihydrogen has high enthalpy due to its stable H-H bond

It is an oxidizing agent when reacting with metals. It forms metal hydrides.

Reacts with unsaturated Hydrocarbon (for example ethene) to form saturated hydrocarbons

Reduces metal oxides of metals less reactive than iron (iron included)

I hope it helps you mate and stay safe

Answer 2

• At room temperature, this diatomic molecule of hydrogen is found in a gaseous state.
• It is a colourless, odourless and tasteless gas, which in turn makes it very hard to detect.
• It is the lightest element of our periodic table.
• It also has the lowest density of all elements.