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Hydrogen

Hydrogen  H

 

 

Where is hydrogen used--or where does it impact our everyday lives?

 

Used in the hydrogenation of oils when manufacturing margarine

 

Used in making ammonia--an important reaction that uses atmospheric nitrogen and hydrogen forming ammonia, NH3.  Ammonia then can be used to make fertilizers, nitric acid and many other materials including explosives.

 

 

 

 

 

 

 

 

 

Hydrogen is made in the lab by the reaction of any reactive metal (any metal other than copper, Cu, silver, Ag, gold, Au, mercury, Hg, or platinun, Pt.)  Some metals are too reactive like lithium, Li, sodium, Na, or potassium, K.

 

Here, hydrogen is being made from zinc reacting with dilute hydrochloric acid by Chemistry One students.

 

 

 

Zn(s) + 2HCl(aq) -->  ZnCl2(aq) + H2(g) and the gas collected in balloons or a Pringle can

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

A spectral tube is a sealed glass tube containing a gas at a low pressure and a high electrical voltage is passed through it.  The electrical energy causes electrons in the gas atoms to be elevated to an excited state--where electrons go to a higher energy level.  As they return to the ground state, their base level, energy is emitted.  The specific wavelengths of energy produce particular colors.

Hydrogen has particular wavelengths of 410, 434, 486 nm towards the blue end of the spectrum and 656 nm at the red end of the spectrum.

WIS Photographer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Look at the image to the left and also SEE THE VIDEO where hydrogen is produced at the cathode in the elctrolysis of dilute sulfuric acid

2H+  + 2e-  -->  H2

The cathode, negative electrode, is made of platinum foil, and is connected to the black terminal of the DC (direct current) power supply.

The hydrogen gas, H2, is in the left-hand tube and there is twice as much hydrogen compared to oxygen gas, O2, collecting in the right-hand tube

 

 

 

 

 

 

 

 

 

 

 

 

VIDEO of making hydrogen from magnesium and dilute hydrochloric acid

Mg + 2HCl -->  MgCl2 + H2

ALL ABOUT HYDROGEN:

Symbol H   At # 1

 

Gas at room temperature

Melting point-259.2 deg C

Boiling point -259.9 degC

Density (at room temp) 1.2929 g/L

Hazard: flammable/ explosive

Reactions with air:

With O2 forms water: 2H2 +O2 --> 2H2O

With heat and a catalyst, N2 forms ammonia: 3H2 +N2 --> 2NH3

Solubility in water-not v. soluble 0.00016 g H2 per 100g water

Electron configuration:  1   one valence electron

Main uses of the element balloons, hydrogen peroxide

Discovered 1776 by Henry Cavendish in London, UK

750,000 parts per million, ppm, in the Universe

 

 

Model of the first gas-filled balloon.  Filled with hydrogen made by reacting scrap iron with sulfuric acid:  Fe + H2SO4 --> FeSO4 + H2

In August, 1783, 3 months before the historic first manned flight by the Montgolfier brothers in a hot-air balloon, Jacques Charles (of Charles" Law fame V1/T1 = V2/T2) launched an unmanned hydrogen balloon that needed a quarter ton of sulfuric acid and 1/2 ton of iron.

On December 1, 1783, less than two weeks after the Montgolfier brothers' balloon flew, Jacques Charles piloted a hydrogen balloon 10 times the volume of the August craft. 

The image of the model here is of a 1/80 scale model made by Charles Newcomen on display in the National Air and Space Museum, Steven F. Udvar-Hazy Center in Chantilly, Virginia, USA.

WIS Photographer

All electronic signs are called "neon" but different gases in the disharge tube, where a low pressure gas is exposed to a high voltage, will produce different colors dependent on the nature/type of gas and whether mercury vapor is also present as well as the nature of the glass.

Hydrogen can form red/pink hues.

WIS Photographer

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