Chemistry Exam Two

Vesper Theory

Types of shapes of molecules: Linear, Bent, Tetrahedral, Trigonal planar, and Trigonal Pyramidal

Linear

CO2, Atoms arranged in a straight line

Bent

H2O, they should be linear, but due to oxygen’s valence electron shell, (electrons don’t like being by each other). The molecule gets bent

Trigonal Planar

SO3, the sulfur would be the central atom and would be surrounded by three atoms. This one doesn’t have a bend so it’s all on one plane. Hence the name planar

Trigonal Pyramidal

This is a central molecule surrounded by three other elements. If the atom has five valence electrons like nitrogen or phosphorus, it would only bond with three elements

Tetrahedral

This is the funkiest structure of them all- it has a central atom and surrounded by four atoms thay are one directly above and then three in a pyramid shape below

Greenhouse Gas

Any gas that contributes to the warming of Earth, this means any molecule that has three or more atoms in it that is a gas in the atmosphere is a greenhouse gas, including, Ozone (O3), Carbon Dioxide (CO2), Methane (CH4), Water Vapor (H2O), and CFCs and HFCs. The most abundant greenhouse gas on Earth is actually H2O. Aerosols (found in spray cans) are known for scattering incoming radiation, nucleating clouds, and absorbing incoming radiation.

They are greenhouse gasses because the infrared radiation that comes off of Earth’s surface is absorbed into their bonds, changing their electric charge distribution

Carbon dioxide attracts water, more carbon dioxide in atmosphere= more water in atmosphere

Kyoto Protocol

The international agreement that attempted to reduce greenhouse gas emissions. Group wanted to stop global warming

Carbon Sequestration

Acts that help pull carbon out of the atmosphere and into a much more dense and stable form. Examples: planting trees, pumping carbon dioxide into the oceans, turning CO2 into dry ice and storing it away. Remember most of carbon is stored on Earth as fossil fuels and carbonate minerals and rocks

Hairspray is a type of aerosol, aerosols absorb incoming radiation

Greenhouse Effect

The sunlight enters into the atmosphere hits Earth and then the energy radiated out by the Earth is absorbed by the atmosphere, the greenhouse gasses return infrared radiation radiated by Earth (Like a thick blanket). Normal two atom gasses like Oxygen (O2) and Nitrogen (N2) do not cause global warming

Answer To Question Nine

In the 2014 report of the intergovernment panel on climate change it was emphasized that Humans are the main factor of global warming since the 50s

Carbon Cycle

The movement of carbon through living organisms, the oceans, minerals in the Earth, and the atmosphere

Industrial Revolution

Important for Earth’s atmospheric history because this is when we first started utilizing fossil fuels in mass, the industrial revolution was in full swing and required the use of a lot of petroleum and coal to help sustain the manufacturing economy we were in at the time

Effects Of Global Warming

If we do not get our CO2 emissions under control the sea ice will disappear, the sea levels will rise, we will see changes in ocean chemistry, and biodiversity will go down

Ionic Compounds

Any metal with a nonmetal, they also form IONS in water very well (hence the name ionic)

Radiative Forcing

Factors that influence the balance of Earth’s incoming and outgoing radiation

Water

70% of Earth’s surface is covered with water, 97% of it is in the ocean, 3% is fresh water, of that 3%, 2% is in the ice caps, so we realistically have 1% for use

Water is composed of H2O, this leads to hydrogen bonding within solutions of water, the hydrogen bonds are responsible for ice having less density than water as a liquid, water also has a high specific heat (amount of energy required to heat it up is insane) and it is also responsible for its high boiling point. Remember, in small quantities hydrogen bonding is pretty weak, but in large numbers the bonds create a strong effect. (Think of the rapid kindergartners we were trying to fight off)

Rain

Rain is acidic because we have carbon dioxide in the atmosphere, it comes together with water to form carbonic acid which gives rain its acidity

Groundwater

Water found underground, usually in aquifers

Covalent Bonds

When electrons are shared between atoms, they can either be polar or nonpolar, if polar, the electrons are shared unequally, if nonpolar, no one wins the tug of war, so the electrons get shared equally

Chlorination

We add chlorine to our water so that we can kill off any bacteria in the water, this continues to protect the water after it leaves the purification plant

Neutralizing Ozone

With aluminum sulfate and calcium hydroxide we are able to neutralize excess ozone in water, the ozone is used to destroy bacteria in the water, and then we have to get rid of the ozone with aluminum sulfate and calcium hydroxide

Distillation

Dirty water is boiled off and condensed in a drip tube to give pure H2O. Pure H2O is not conductive

Electrolytes

Any solute that is is dissolved in water that will conduct electricity. Really good electrolytes are ionic bonds like salt such as NaCl, LiF, NaBr, KCl. Weak conductors are usually molecules that don’t separate into ions very well. AKA (nonpolar things)

PH Scale

Seven is neutral, one is very acidic an example of an acid is hydrochloric acid (found in stomach) a weak acid is acetic acid (vinegar) or Citric acid (found in lemon juice). 14 is very basic, a strong base has a lot of hydroxide ions, example is NaOH (Lye). Ammonia is a weaker base. Oceans are basic, rain is acidic. Most sea life cannot survive in water with a pH of less than five. Every increase in pH unit indicates ten times less hydrogen ions. Remember what was said about pH. It stands for the potential of hydrogen. If one is acidic and it means it has the most hydrogen ions to donate. If you go to the right it has less hydrogen ions

Mass Percent Formula

Find molar mass of an element in the formula and divide by the mass of entire compound. (NaOh)- Na has a mass of 22.989, O has a mass of 15.999, and H has a mass of 1.008. So altogether the mass is equal to 39.996 (just added all the masses together). If you want the mass percent of oxygen then you would take oxygen’s mass and divide by the whole. So 15.999/39.996= .40001 (so 40%)

Formula For Molarity

Moles of solute/ Liters of solutions

Make sure you can do the formula if they give you grams. So if you have grams of something, be able to convert it to moles, if you are given mL of liquid be able to convert to liters