Hydrogen and Oxygen

Information and UsesUnit 2 - Mission to Mars Connection

Hydrogen is the lightest and most

abundant element in our universe.

Hydrogen does not exist by itself in

nature• Hydrogen exists as parts of compounds

• Hydrogen is part of many compounds such as the compounds that make up:• Fossil fuels(oil, coal, natural gas)• plants• water

Uses for hydrogen

• Thermonuclear energy ( Sun)

• A lifting agent (Hindenberg blimp)

• Fuel• Cars• Rocket fuel

Oxygen

•  Oxygen is a tasteless gas.

• It has no smell or color.

• It is the 3rd most abundant element in the universe

• It comprises 22% of the air we breathe

• This element is found in the human body, the Sun, oceans and the atmosphere.

• Without oxygen, humans will not be able to survive.

Uses for Oxygen

• Of all the uses of oxygen, sustaining life is the most important.

• Oxygen is needed by all living organisms.

• Through a process known as aerobic respiration, energy from food is generated.

• This allows humans and animals to perform their daily activities.

Water (H2O)

• Water is the most abundant compound on Earth

• It is made up of 2 hydrogen atoms and 1 oxygen atom that are chemically bonded together

• The ratio of hydrogen to oxygen is 2:1 which means there is twice as much hydrogen as oxygen

A water molecule is made up of one

oxygen atom sharing electrons with

two hydrogen atoms.

Water

•A water molecule is formed by two elements: two positive Hydrogen ions and one negative Oxygen ion.

• The water molecule is held together by the electromagnetic attraction between these ions.

Water exists as a compound so it can not

be separated by physical means

Hydrogen and oxygen can be separated from water by electrolysis

Electrolysis

• Electrolysis is a method of using a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. 

Electrolysis

• When electricity is introduced to water through two electrodes, a cathode (negative) and an anode (positive), these ions are attracted to the opposite charged electrode.

• The positively charged hydrogen ions will collect on the cathode and the negatively charged oxygen will collect on the anode. 

Electrolysis

• When these ions come into contact with their respective electrodes they either gain or lose electrons depending on their ionic charge.

• In this case the hydrogen gains electrons and the oxygen loses them

• In doing so these ions balance their charges, and become real, electrically balanced, bona fide atoms (or in the case of the hydrogen, H2, a molecule).

Electrolytes

• Pure water itself is not a good conductor of electricity, so in our experiment baking soda will be added to make the solution an electrolyte.

• An electrolyte is a part of a solution that can be broken up by electrolysis. 

• Electro refers to energy and electricity and -lysis refers to splitting apart.

Diagram of Electrolysis Set up