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