PYS 100 Unit 3

What do aspirin, naproxen, and ibuprofen have in common (as seen in Fig. 19.5)

single bonds double bonds benzene-like rings oxygen atoms

Bonding

when atoms get near each other, their orbitals overlap and new orbitals are formed

Principles of Chemical Reactivity

-All chemical interactions are from electrostatic interactions -negative electrons and positive nuclei cause atoms and molecules to interact with each other for form bonding

Dispersion Forces

-Between nonpolar molecules -Temporary shift of electrons creating slight polarity -increase with the size of the molecule

Dipole-Dipole Forces

-Between polar molecules -Positive attracted to negative and vice versa

Magnesium and Oxygen react to form Magnesium Oxide. What do the electrons do during the reaction? Let's pretend that we have some of . this stuff in this room right now. Explain in detail at least four of its properties

-Brittle -Transparent -Solid -Non-conductive ( unless dissolved)

IR Spectrometer

-Infrared light is shone through some sample -the light transmitted through the sample is detected

Most wiring in your house is likely copper wiring. Explain at least three reasons why copper, or more broadly metal is used

-metals conduct electricity -metals have high melting temperatures -Metals are malleable and ductile, meaning they can be molded and stretched into thin wires without breaking

Irreversible process

-the total disorder of the universe increases -if it doesn't make sense played backwards, then it is irreversible

Reversible process

-the total disorder of the universe remains constant -If it makes sense played backwards, then it is reversible

We have a lot of different energy sources out there. Rank the following in terms of efficiency. Our goal is to get Electric Potential Energy: Coal/ Natural gas Wind Nuclear

Coal/ Natural gas (3) Wind (1) Nuclear (2) (this is from the article)

Semiconductor

Elements that are not quite metals and not quite non-metals -B, Si, Ge, As, Sb, Te, Po, -along the staircase on the periodic table -still have similar properties to metals

Intermolecular forces

Forces between molecules that hold them together 1. Dispersion Forces 2.Dipole-Dipole Forces 3. Hydrogen bonding

Order of Energy (highest to lowest)

Gravitational Potential, Kinetic Elastic Nuclear Potential Electric Potential Chemical Potential Thermal

Metallic bonding

metal + metal -"Sea of electrons" -Opaque -Malleable -Conductor -High melting and boiling point

Ionic bonding

Metal + Nonmetal -"electrons are stolen" -transparent -brittle -non-conductor(unless dissolved)

Alloys

Mixing two metals -Bronze= copper + tin -Brass= Copper + Zinc -Coin metals= Copper+ Aluminum+ Nickel (same bonding structure but usually stronger)

Covalent bonding

Nonmetal + Nonmetal -"electrons are shared" -Transparent -non-conductor -low melting and boiling point

Element

One atom from the periodic table examples: C, N, O, Na, Fe

Hydrogen Bonding

Polar molecules that have H bonds bonded to F,O,N -When you melt or boil covalent material, you are breaking the attraction between molecules, or breaking intermolecular forces -Intermolecular forces are not as strong as actual bonds and are broken easier -the stronger the intermolecular force, the high the melting and boiling point

Diatomic Molecules

Some elements dont like to be alone H, N, F, O, I, Cl, Br Have No Feat Of Ice Cold Beer

You put room temperature water into an ice-making tray and put it into your freezer. As the water cools and then becomes a solid, what happens to the entropy of the universe?

The entropy of the universe goes up

Compound

Two or more elements bonded together, a mixture examples: NaCl, FeO, CuZn

Molecule

a group of elements bonded together in specific ratios with specific bonds H2O, CO2, CH4

Entropy

a measure of the disorder of a system Chemical reactions always increase the total entropy of the universe

Which of the following is atomic matter rather than molecular or network matter? Select one a. Neon gas b. water c. magnesium chloride d. silver e. white gold

a. Neon gas

A window air conditioner is normally placed in a window so the hot air from the back blows outside. What would happen if the air conditioner were placed in the middle of a closed room and turned on? Select one: a. The room would heat up because all of the energy absorbed by the air conditioner, both thermal and electrical potential, is released back into the room as thermal energy. b. The room would heat up because the electrical potential energy loses entropy while the room gains entropy. c. The temperature of the room would stay the same because internal energy is conserved. d. The room would cool down because as the entropy of the electrical potential energy increases, the entropy of the room must decrease to compensate. e. The room would cool down because the electrical potential energy from the outlet decreases the ambient thermal energy in the room.

a. The room would heat up because all of the energy absorbed by the air conditioner, both thermal and electrical potential, is released back into the room as thermal energy.

Each molecule of nitric acid has the formula HNO3. If there are 6000 oxygen atoms present and 6000 nitrogen atoms present, how many hydrogen atoms will be required to convert all of the oxygen atoms into nitric acid? Select one: a. 1000 b. 2000 c. 4000 d. 6000 e. 18000

b. 2000

Which type of energy listed below is the most ordered? Select one: a. Nuclear potential energy b. Gravitational potential energy c. Thermal energy d. Chemical potential energy e. Impossible to tell without more information about the process.

b. Gravitational potential energy

Mass Spectroscopy

break up molecules charged pieces accelerated to magnets larger pieces detected and mass measured Masses of different fragments of original molecule placed on a graph

In an irreversible process, the overall disorder of the universe Select one: a. is constant. b. decreases. c. increases. d. is zero. e. becomes infinite.

c. Increases

Which of the following tends to have the highest melting and boiling points? Select one:. a. Atomic matter b. molecular matter c. network matter

c. network matter

Which of the following is not a compound? A.sulfur dioxide B.nitrous oxide C.water molecule D.oxygen molecule E.rust

c. water molecule

The 2nd Law of Thermodynamics (Law of Increasing Disorder) places limits on the efficiency of energy conversion. Which of the following is allowed? Select one: a. 100% conversion of ambient temperature thermal energy to kinetic energy. b. 100% conversion of chemical potential energy to kinetic energy. c. 100% conversion of sunlight to kinetic energy. d. 100% conversion of electricity to ambient temperature thermal energy. e. 100% conversion of ambient temperature thermal energy to chemical potential energy.

d. 100% conversion of electricity to ambient temperature thermal energy.

The gasoline engine of an automobile is considerably less than 100% efficient. This means that not all of the energy in the gasoline is turned into kinetic energy of the car. Which of the following best explains why? Select one: a. Engineers and scientists have not yet managed to make it more efficient, but there is no scientific reason it cannot be 100% efficient. b. There is too much friction in the engine and the rest of the automobile. If it were not for this friction the efficiency would be 100%. c. All engines (that is electric motors, gasoline engines, steam power generators burning gas or oil, etc) have exactly the same efficiency, which is, of course, less than 100%. d. Some of the chemical potential energy in the gasoline must become ambient thermal energy if the rest is to supply the kinetic energy of the automobile. This means some energy must be wasted. e. Actually the automobile engine is nearly 100% efficient as long as the automobile is traveling on the level. When it climbs up a hill, however, the efficiency drops because of the changing gravitational potential energy

d. Some of the chemical potential energy in the gasoline must become ambient thermal energy if the rest is to supply the kinetic energy of the automobile. This means some energy must be wasted.

Which of the following processes is closest to an ideal reversible process? Select one: a. Two cars colliding. b. Using a toaster to make toast. c. A pendulum swinging. d. A ripe peach rotting. e. An ice cube floating in a glass of water at zero degrees.

e. an ice cube floating in a glass of water at zero degrees