Studied by 0 people4 properties of hydrogen
non-toxic, burned with oxygen- products are non toxic, not harmful, releases a lot of energy
hydrogen is an energy source that..
can not be stored as it is
electricity from renewable sources such as wind and solar, produce
hydrogen
what is energy density
How much energy per kilogram
hydrogen fueled cars give more energy than gasoline fueled cars
true
what is one advantage of hydrogen fueled cars
2-3x more efficient due to the fuel cell and electric motor
what is the name for a typical fuel cell called
stack
what famous airship exploded showing the dangers of hydrogen
Hindenburg
what are benefits of hydrogen
less dense than air, oder and colorless, diffuses into metal
what does being less dense than air mean for hydrogen
H flames aren't as hot as gas flames and temps have to be extremely hot for H to spontaneously ignite
what happens when hydrogen diffuses into metal?
the metal become brittle
what is green energy
no polluting by-products, no hazardous waste, no danger to the environment
what are the two main processes hydrogen is used in
oil refining, making ammonia for fertilizer
what process is used to obtain hydrogen from natural gases
steam reformation
where does the electricity from electrolysis come from
hydroelectric dams, wind, nuclear plants, coal, oil
what are the two portions of the future of hydrogen economy
substantial portion and how to get the hydrogen
how do obtain hydrogen from green methods?
by taking and using the electricity from a non-pollution renewable source you split the hydrogen and oxygen atoms from water
what is another method to obtain hydrogen
getting hydrogen from a fossil fuel then capturing and storing the co2 that was also released
what does water split into if you split it using electricity
H2 + O2
hydroelectricity
from solar wind - water electricity and is 1/6 of total electricity
what would you need to replace gas cars with H2 cars
68% more electricity than is currently produced
If electric plants were all 'GREEN', how much would carbon footprint decrease?
47% If same mix of coal, oil natural gas it would reduce carbon footprint by ~17%
What can a solar system do?
knock power out for 2-3 weeks over large area of land (37 states +)
coronal mass ejection
What is a coronal mass ejection?
gigantic glob of charged particles spit out by the storm
What would the charged particles spit out by the coronal mass ejection do?
it would destroy electric generators, transformers, radiosity, cell phones and communications satellites because they would be overwhelmed with voltage and be destroyed
When was the last solar storm and how much did it miss the earth by?
2012 Missed earth by 1 week
When did a CME hit the earth?
1859
What effect did the CME have on the earth in 1859?
northern light displays 2) telegraph systems went down - they weer overloaded by electric current and burned down
If the CME glob of particles hits the earth what will happen? (name 7)
ALL electonic communication will be gone (radio, internet, cell phones, tv)
One variety of electrical charge is a Positive electric charge what is it also called?
Proton = Positive charge
The second variety of electric charge is a Negative charge what is it also called?
Electron = negative charge It is also the smallest common particle
Where are the protons and electrons located?
nucleus
Movement of electrons is known as what?
electricity
How much larger is a proton than an electron?
800x heavier
Any moving charged particle produces what?
electricity
Electrons are on the surface of an atom and determine what? Notes say size and convenient location is why it is viewed this way
Size of an atom and the space that it occupies
What two types of electricity are naturally occurring?
Lightning and Static
What causes lightning?
Small droplets of water or ice particles collide and the electrons get stripped off and accumulate in it
Lightning - voltage, amperage and length of time
voltage: 100 million volts in comparison to a house that has 120 volts
How was static electricity originally produced?
Amber being rubbed with silk which strips the electrons resulting in POSITIVELY charged amber (resinous electricitry)
What did positively charged amber attract?
small feathers and bits of thread
What is produced when glass is rubbed with wool?
Vitreous electricity It is NEGATIVELY charged
What is the problem with naturally occurring electricity?
Doesn't last long
Compare lightning voltage to static voltage
Lightning: 100 million volts
Who discovered muscle contractions without static charge?
Galvani -- explained that animals posses a certain quantity of electricity
Who disagreed with Galvani's theory?
Volta
What was Volta's argument against Galvani's theory?
It was the tools Galvani used in his experiments. Battery amount of voltage lasts a long time and hydrogen and oxygen bubbles were given off
Who did the electrolysis of water experiment?
Davy and his assistant was Michael Faraday
What was Davy's electrolysis of water experiment?
Molten salt that he ran an electric current through. One side sodium metal the other side chlorine (Na Cl)
What is electrolysis of water?
Splitting Water into Hydrogen and Oxygen using electricity. This hydrogen created can be used as hydrogen fuel or oxyhydrogen gas used in welding. The total energy of the reaction is increased with heat thereby using less electricity to split the water.
Who was Michael Faraday?
Davy's assistant. The last self taught non mathematics scientist of the 1800s
What did Michael Faraday believe?
Fixed relationship between each element and the amount of electricity required to produce the element from compounds.
Which of Michael Faraday's experiments is still used today?
Electroplating
What is electroplating?
producing a thin metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. Uses oxidation and reduction
What is Redox?
Where electrons get transferred between 2 materials
What is the movement of electrons called?
Electricity
What is oxidation?
giving up or losing electrons
What is reduction?
material gaining or accepting electrons
What are oxidation numbers?
Book keeping tool to follow electron movement (is known as the total number of electrons that an atom either gains or loses in order to form a chemical bond with another atom)
In a pure element, what is the oxidation number?
Zero
What is a pure element's chemical symbol and charge?
Single Chem symbol and No charge
Give an example of two elements?
Fe and O2 (Iron and oxygen)
Give an example of a chemical formula for a compound
FeO (ferrous oxide)
Give an example of an ion (not an element)
Fe^+3 if it has a charge listed it is an ion
What is a simple ion?
It is a single atom with a charge
List several simple ions and their charges
O.N. oxidation number no charge
Group IA elements all have the following oxidation number and list them
+1 6 elements - Li, Na, K, Rb, Cs, Fr all are +1
Hydrogen is what ON
+1
Oxygen is what ON
-2
Group VIIA is what oxidation number, and list the elements in VIIA?
-1 F, Cl Br, I, At, Ts All are -1
What charge is Hydrogen?
+1
what charge is Oxygen?
-2
How many elements are there?
118 (98 of these are naturally occurring)
How many elements' oxidation numbers/charges stay the same?
14
How many elements do not follow the oxidation number rule?
104 the ON changes during chemical reactions
In a NEUTRAL compound what is the charge?
Zero - it is neutral - no electric charge (the pos and neg charges cancel each other out to equal no charge)
For a CHARGED compound, how is the charge found?
Total Pos + Total Neg = charge sign and size
Configured on the number line LEFT to RIGHT is what?
OXIDATION
configured on the number line RIGHT to LEFT is what?
REDUCTION
In a Redox reaction problem anything that is not __________gets balanced normally.
H2O (water)
How does missing oxygen get balanced?
by adding H2O (water)
How does missing H (Hydrogen) get balanced?
By adding H+ (hydrogen)
How do you equalize the charge in redox reaction problems?
By adding electrons
If E cell is positive
spontaneous (producing voltage)
If E cell is negative
non-spontaneous (not producing voltage, electricity must be supplied)
capaseter
device that store electrons
E reduction - E oxidation=
E cell
alkaline batteries
same chemical reaction and voltage (1.5) *only differ in size
Note
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