CHEMISTRY COMMUNITY

Krista Mercado 1B

Lyndon and Karen's workshops are usually the most helpful for me.

Krista Mercado 1B

A bimolecular reaction involves two reactants. This is an example of a second-order reaction.

Krista Mercado 1B

The difference is that k is Boltzmann's constant, while K is the equilibrium constant for a given reaction.

Krista Mercado 1B

You would include H+ and OH-, but not H2O

Krista Mercado 1B

The compound that is reduced is considered the oxidizing agent. The compound that is oxidized is the reducing agent.

Krista Mercado 1B

You would include H+ but not H2O

Krista Mercado 1B

This equation is used to find the change in entropy for isothermal reversible reactions.

Krista Mercado 1B

When the charge changes from +2 to +4, that means the atom has lost 2 electrons. Since there is a loss of electrons, this is an example of an oxidation reaction.

Krista Mercado 1B

Galvanic cell is just another name for a voltaic cell.

Krista Mercado 1B

The equation to find entropy is S=kblnW, where W=(# of microstates)^(# of molecules)

Krista Mercado 1B

It can exchange both matter and energy with its surroundings.

Krista Mercado 1B

Extensive properties depend on the amount of matter being measured. On the other hand, intensive properties do not depend on the amount of substance present.

Krista Mercado 1B

Danny Elias Dis 1E wrote:Is this situation also the case where deltaU = q?

Yes, because ΔU = q+w, and if w = 0, then ΔU = q+0 = q.

Krista Mercado 1B

This mean that internal energy depends only on the current state of the system and is independent of how that state was prepared. Other examples of state functions are pressure, volume, temperature, and density.

Krista Mercado 1B

This is the case when the change in internal energy is 0

Krista Mercado 1B

Increasing pressure will cause the reaction to proceed towards the side with less moles of gas.

Krista Mercado 1B

A closed system has a fixed amount of matter, but can exchange energy with its surroundings. An isolated system there cannot be transfer of energy or matter between a system and its surroundings. An open system can freely exchange matter and energy with its surroundings.

Krista Mercado 1B

E stands for equilibrium concentration.

Krista Mercado 1B

The question will tell you which to solve for.

Krista Mercado 1B

Q and K are calculated the same way. If Q<K, then the reaction will tend to proceed towards the products. If Q>K, then the reaction will proceed towards the reactants.

Krista Mercado 1B

I think the solution is considered neutral if [H3O+] is equal to 10^-7. If it is less than that, then it is considered a basic solution.

Krista Mercado 1B

By comparing Q to K, it will tell you whether the reaction will proceed forward, backward, or is already at equilibrium If Q = K, then the reaction is at equilibrium If Q < K, then the reaction will favor the products (proceeds forward) If Q > K, then the reaction will favor the reactants (proceeds ...

Krista Mercado 1B

The reaction quotient, Q, tells you the ratio of products to reactants at any given instant. The equilibrium constant, K, gives you the ratio of products to reactants when the reaction is at equilibrium.

Krista Mercado 1B

No, solids and liquids are not included in Q or K.

Krista Mercado 1B

It's important to note that different initial concentrations of a reaction does not affect the equilibrium constant.

Krista Mercado 1B

We can use either partial pressure or concentration to calculate K, but partial pressure can only be used in gas phase reactions.

Krista Mercado 1B

Yes, brackets are used specifically in equilibrium expressions to indicate the concentration of a certain substance.

Krista Mercado 1B

You would have to convert the amount of grams of the limiting reactant to moles, then compare the ratios of the reactants in the balanced equation to figure out how many moles of the reactant are required.

Krista Mercado 1B

What are some examples of amphoteric compounds?

Krista Mercado 1B

The pH formula is pH = -log[H+]. I don't think we need to know how it is derived.

Krista Mercado 1B

I think we need to memorize the charges of the ligands as well.

Krista Mercado 1B

Thank you so much for the final review and practice problems!

Krista Mercado 1B

A Lewis acid is an electron acceptor and a Lewis base is an electron donor.

Krista Mercado 1B

A Lewis acid is an electron acceptor, and a Lewis base is an electron donor. On the other hand, a Bronsted acid is a proton donor, and a Bronsted base is a proton acceptor. The definition that you use just depends on whether you're focusing on the transfer of electrons or protons.

Krista Mercado 1B

I don't know if we'll have to remember all of them, but Dr. Lavelle said that there is a diagonal band of amphoteric oxides, between the metal oxides and nonmetal oxides, that closely matches the diagonal band of metalloids.

Krista Mercado 1B

Greater polarity between molecules leads to a stronger dipole moment. This means that the larger the difference in electronegativity of the bonded atoms, the larger the dipole moment.

Krista Mercado 1B

Yes. With multiple bonds, there is only one sigma-bond and each additional bond is a pi-bond. For a double bond there is one sigma-bond and one pi-bond.

Krista Mercado 1B

The pi-bond would break first since pi-bonds are weaker than sigma-bonds. This is because the side-by-side overlap in a pi-bond is smaller and weaker than the end-to-end overlap in a sigma bond.

Krista Mercado 1B

What is the relationship between sigma/pi bonds and hybridization?

Krista Mercado 1B

Dipole-dipole forces occur between polar molecules when the positive end of one is attracted to the negative end of the other and vice-versa.
London forces occur between all types of molecules (polar and non-polar) and are weaker than dipole-dipole forces.

Krista Mercado 1B

RoopshaChatterjee 1G wrote:Can the sigma/pi bonds also be used to determine the structure of the molecule?

Sigma and pi bonds can't be used to determine the structure of a molecule since they do not affect shape or structure.

Krista Mercado 1B

When there is a lone pair, why does this make the bond angle smaller? Also, how do you determine how much smaller the bond angle will be?

Krista Mercado 1B

Since a resonance hybrid is a blend of Lewis structures, all the bond lengths are the same. Thus, even though there are both single and double bonds in the resonance structure, all of the bond lengths will be the average between the different bond lengths of the structure. For this specific question...

Krista Mercado 1B

How can you determine if a certain compound requires a resonance structure?

Krista Mercado 1B

You can determine this by looking at the difference in the electronegativity of the atoms involved in the bond. The bond with a greater difference in electronegativity has a greater ionic character.

Krista Mercado 1B

Why is the ground state electron configuration of copper [Ar]3d^(10)4s^(1) and not [Ar]3d^(9)4s^(2)?

Krista Mercado 1B

How does resonance help to stabilize the molecule?

Krista Mercado 1B

Give the ground-state electron configuration and number of unpaired electrons expected for each of the following ions:
(a) Sb3
(b) Sn4
How do you find the number of unpaired electrons?

Krista Mercado 1B

Why are electrons that are further away from the nucleus easier to remove? The nucleus has a positive charge, which attracts negatively charged electrons. If electrons are farther away from the nucleus, this positive nuclear charge is weaker, so the electrons aren't pulled as tightly towards the nu...

Krista Mercado 1B

I don't think we need to know the specific shapes of the f orbitals, we just need to know that it has 7 different orbitals which hold a total of 14 electrons.

Krista Mercado 1B

This is because the 4s orbital is slightly closer to the nucleus, and thus has a slightly lower energy than the 3d orbital. This means that the 4s orbital will be filled before the 3d orbital. This concept applies to the elements Calcium (Ca) and Potassium (K).

Krista Mercado 1B

A node is where the probability of finding an electron is zero.

Krista Mercado 1B

I know we do not have to know how to use the Schrodinger Equation in calculations, but what specifically do we need to know about the equation?

Krista Mercado 1B

I agree with Emily, I think the Balmer series and the Lyman series are the two that we need to know. The Balmer series corresponds with the visible region of the spectrum, and electrons come to rest at energy level n=2. The Lyman series corresponds with the ultraviolet region, and electrons come to ...

Krista Mercado 1B

In the 12-1 lecture Dr. Lavelle also said wavelike properties are measurable when the De Brogile wavelength is at least (some value)x10^-18.

Krista Mercado 1B

The energy that was lost is released as electromagnetic radiation, which is why the change in energy is negative.

Krista Mercado 1B

Constructive interference is when two waves meet in a way that their crests line up. This results in a wave of a higher amplitude. On the other hand, destructive interference is when the crest of one wave meets with the trough of the other. This results in a wave of lower amplitude.

Krista Mercado 1B

I remember Dr. Lavelle saying that we will be given a periodic table for the test, and we can use that to calculate the molar mass of the elements and compounds.

Krista Mercado 1B

When should we apply the rules of significant figures? Do we use them throughout the problem or just for the final answer?

Krista Mercado 1B

How do you calculate the net number of moles produced in a balanced chemical reaction?

Search found 60 matches