Properties Of Dihydrogen
Chapter Name : Hydrogen |
Sub Topic Code : 102_11_09_04_02 |
Topic Name : Properties Of Dihydrogen |
|
Sub Topic Name : Chemical Properties |
|
Introduction
The solubility and characteristics of hydrogen
with various metals are very important in metallurgy (as many metals can suffer
hydrogen embrittlement) and in developing safe ways to store it for use as a
fuel.
Pre-Requisites:
Combustibility, Dissociation
Activity:
Hydrogen is highly combustible gas and burns in air with a pale blue
flame to form water.
Real Life Question:
How is the chemical reactivity of metals linked
with their position in the electrochemical series?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Dissociation | Dissociation is an act of disuniting or separating a complex object into parts. |
| Combustibility | Combustibility is a measure of how easily a substance will set on fire, through fire or combustion. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Water, drain clog removal (containing sodium hydroxide) + aluminium foil | When water is added to a drain clog removal liquid in the presence of aluminium ( using aluminium foil) , hydrogen gas is liberated. This is an exothermic reaction. |
Real life uses :
·
It is used for the manufacturing of fertilizers.
·
It is used in the preparation of vegetable ghee.
It is used as rocket
fuel.
Places to visit :
Chemistry lab
Practical examples around us
| Examples | Explainations |
|---|---|
| Hydrogen as a fuel | Hydrogen is commonly used in the petroleum and chemical industries and is also widely used for many physics and engineering applications such as welding or as a coolant. |
What you learn in Theory:
Hydrogen gas forms explosive mixtures with air if it
is 4–74% concentrated and with chlorine if it is 5–95% concentrated. The
mixtures spontaneously explode by spark, heat or sunlight. The hydrogen autoignition temperature,
the temperature of spontaneous ignition in air, is 500 °C (932 °F).
What you learn in Practice:
·
With dinitrogen hydrogen forms ammonia (NH3).
Dihydrogen reacts with strongly electropositive
metals like sodium, calcium etc. to form salt like metal hydrides, in which the
oxidation state of hydrogen is -1.