Search found 19 matches

by Kyle Reidy 3H
Sun Dec 10, 2017 9:04 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Replies: 1
Views: 254

Re: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions

We calculate Q for this reaction by the formula \frac{[SO_{3}]^{2}}{[SO_{2}]^{2}[O_{2}]} . If we plug in our given values, we find Q = 5.0 * 10 11 , which is less then our given K, so the reaction is not at equilibrium. The reaction will move right, or favor the forward reaction, so that it will con...
by Kyle Reidy 3H
Sun Dec 10, 2017 8:56 am
Forum: Formal Charge and Oxidation Numbers
Topic: Quick Determination of FC [ENDORSED]
Replies: 6
Views: 358

Re: Quick Determination of FC [ENDORSED]

To clarify, I thought of the number of protons past the most recent noble gas, as any "earlier" proton would be canceled by the inner shell electrons.
by Kyle Reidy 3H
Sun Dec 10, 2017 8:48 am
Forum: Formal Charge and Oxidation Numbers
Topic: Quick Determination of FC [ENDORSED]
Replies: 6
Views: 358

Re: Quick Determination of FC [ENDORSED]

I personally found it very helpful to think about how many protons were in the nucleus of the atom. We compare this with the number of electrons surrounding the nucleus, halving any "shared" electrons. If the atom has more electrons than protons, we know the formal charge to be negative. I...
by Kyle Reidy 3H
Sun Dec 10, 2017 8:43 am
Forum: DeBroglie Equation
Topic: Wavelike properties
Replies: 3
Views: 155

Re: Wavelike properties

This limitation is primarily due to the precision of modern measuring equipment.
by Kyle Reidy 3H
Sun Dec 10, 2017 8:27 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Changing Stoichiometric Coefficients
Replies: 2
Views: 279

Re: Changing Stoichiometric Coefficients

Yes, I understand that part, but it's more a conceptual question. I would have thought that as long as the ratio remains the same, it wouldn't matter if you doubled every stoichiometric coefficient or put Avogadro's number in front of every coefficient. Maybe I'm confused about the definition of the...
by Kyle Reidy 3H
Sat Dec 09, 2017 11:14 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Changing Stoichiometric Coefficients
Replies: 2
Views: 279

Changing Stoichiometric Coefficients

One of the questions on the practice final asked how the equilibrium constant would change if we halved all the stoichiometric coefficients. The answer is that we would ultimately get the square root of the original constant. This concept is confusing me though. I believed we could always write some...
by Kyle Reidy 3H
Thu Dec 07, 2017 4:36 pm
Forum: Hybridization
Topic: sp2 hybridization
Replies: 5
Views: 199

Re: sp2 hybridization

Then, just to be clear, the boron atom now has an "empty" p orbital? I realize these aren't real compartments, but that's the best way I understand it at the moment.
by Kyle Reidy 3H
Sun Dec 03, 2017 10:38 pm
Forum: Ideal Gases
Topic: Bar
Replies: 3
Views: 294

Re: Bar

1 bar is slightly smaller than 1 atm, but the units are approximately equal to each other. atm is sometimes called the "standard pressure," despite the fact that that pascal is the SI derived unit of pressure.
by Kyle Reidy 3H
Sun Dec 03, 2017 10:23 pm
Forum: Ideal Gases
Topic: Partial Pressure
Replies: 4
Views: 536

Re: Partial Pressure

We use partial pressure often in calculations regarding chemical equilibrium. Just as you would use the molarity of different chemicals to calculate the composition of an aqueous solution, we use the partial pressures of gases to calculate the composition of the gases.
by Kyle Reidy 3H
Sun Nov 26, 2017 10:42 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: KC/KP/QC/QP
Replies: 2
Views: 852

Re: KC/KP/QC/QP

Some of the difference can be seen in the names. We call Q the reaction quotient and K the equilibrium constant. "Constant" implies that this value does not change – it is a set value that the reaction wants to attain for the given set of conditions – while Q can have different values thro...
by Kyle Reidy 3H
Sun Nov 26, 2017 10:35 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: units for pressure
Replies: 1
Views: 117

Re: units for pressure

The SI unit for pressure is the pascal, equal to one kg.m-1.s-2. This makes sense when we consider the other components of the ideal gas law, like the gas constant R, which has units of kg.m2.mol-1.degrees K-1.s-2.
by Kyle Reidy 3H
Mon Nov 06, 2017 11:59 am
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 10
Views: 337

Re: Lewis Structures

To confirm, the center atom is the one with the lowest ionization energy. Take methane for example, which is one atom of carbon bonded with four atoms of hydrogen. We know carbon is the central atom, so let's compare the ionization energies and electronegativities: ..............Ionization Energy (k...
by Kyle Reidy 3H
Mon Nov 06, 2017 11:46 am
Forum: Ionic & Covalent Bonds
Topic: Characterization [ENDORSED]
Replies: 2
Views: 143

Re: Characterization [ENDORSED]

In an ionic bond, the electron(s) that left the cation for the anion can be considered to "belong" completely to the anion, but in a covalent bond, the electrons are shared between the two atoms. When one atom's electronegativity is stronger than the other's, this sharing is uneven, and th...
by Kyle Reidy 3H
Fri Oct 27, 2017 1:01 am
Forum: Ionic & Covalent Bonds
Topic: Ionic vs. Covalent Bonds [ENDORSED]
Replies: 8
Views: 386

Re: Ionic vs. Covalent Bonds [ENDORSED]

Lewis Diagrams are actually quite helpful in ionic bonds, because we can visualize the electron leaving one element to go to the other. This is why we made a Lewis Diagram in class for sodium chloride (K+ Cl-).
by Kyle Reidy 3H
Fri Oct 27, 2017 12:57 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Possible Values of l: Do they go higher?
Replies: 2
Views: 117

Possible Values of l: Do they go higher?

We were told that the angular momentum quantum number could have values from l=0 to n-1. The periodic table includes elements that have some electrons in states all the way up to n=7, but we have only talked about the s, p, d, and f orbitals corresponding to l=0, 1, 2, and 3, respectively. Is there ...
by Kyle Reidy 3H
Fri Oct 13, 2017 1:23 am
Forum: Properties of Electrons
Topic: Energy Levels [ENDORSED]
Replies: 2
Views: 202

Re: Energy Levels [ENDORSED]

A photon has a discrete amount of energy, E = hv. This number is always positive, since the photon cannot have "negative" energy. When an atom emits a photon, it loses an amount of energy, so yes, ΔE for the atom would be negative. We describe this loss of energy as the emission of a posit...
by Kyle Reidy 3H
Fri Oct 13, 2017 1:12 am
Forum: Properties of Light
Topic: Speed of Light Constant
Replies: 18
Views: 587

Re: Speed of Light Constant

Professor Lavelle told my TA that we would be given constants on the tests. He didn't specify which ones, so I assume the speed of light will be there as well. However, just in case, this may be a good one to have memorized, since it's pretty simple.
by Kyle Reidy 3H
Wed Oct 04, 2017 4:34 pm
Forum: SI Units, Unit Conversions
Topic: Molecules [ENDORSED]
Replies: 10
Views: 451

Re: Molecules [ENDORSED]

The textbook says that a mole of something has the same number of atoms in carbon-12, which is 6.02x10^23 atoms. @304938418, A mole of something has the same number of atoms as 12 grams of carbon-12. Carbon-12 is an isotope (I'm sure we'll review this later in the quarter), so there are singular at...
by Kyle Reidy 3H
Wed Oct 04, 2017 4:27 pm
Forum: Significant Figures
Topic: If last digit is 5: round to nearest even number?
Replies: 2
Views: 307

Re: If last digit is 5: round to nearest even number?

The reason we do this is so that we introduce less error when we round numbers. 5 is not closer to 10 than it is to 0, and it is only by convention that most people round 5 up to 10. However, this means that every number you round in this way would be slightly over the real value and your data will ...

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