CHEMISTRY COMMUNITY

Minsub Lee 3E

Yes, like what most people said, the molecule is nonpolar unless the bonded atoms are not uniform. An example of this is CH4 and CClH3. Although both molecules have a tetrahedral molecular shape, CClH3 is polar because the partial charge given by the electronegativity difference of the chlorine atom...

Minsub Lee 3E

Yes, it is the other way. Every Bronsted Acid fits the definition of a Lewis acid, but is not true for the reverse.

Minsub Lee 3E

Water can both act as an acid or base depending on the chemical reaction. When reacting with HCl, it acts as a base because it is accepting the H+ from HCl to form H3O+. However, when reacting with NH3, it acts as an acid because it is donating a proton to NH3 to form NH4.

Minsub Lee 3E

Use sig figs according to the concentration value. If the concentration of H+ is 3.2, then the answer should be in 2 sig figs.

Minsub Lee 3E

@joanneyseung22 If there are lone pairs on the central atom, it will want to take up more space. Therefore, the bonded atoms will be condensed away from the lone pairs. Therefore, the bond angle will be slightly less than the standard bond angles of the molecular shape.

Minsub Lee 3E

For this class, a good way to differentiate between strong acids/bases from weak acids/bases is by memorizing the strong ones. Only a few acids and bases are strong. If you do not recognize the acid as a strong acid, it is most likely a weak acid.

Minsub Lee 3E

Bases react with cells in skin, dissolving the fatty acids and oils from your skin; therefore, it decreases the friction between fingers when rubbing together.

Minsub Lee 3E

For sake of saving time of future exams, I would say that it is best to memorize the shapes.

Minsub Lee 3E

'A' refers to the central atom, 'X' refers to the bonded atom, and 'E' refers to lone pair. By knowing how much of each are there, you can determine how many atoms and lone pairs there are, and then determine the shape of the molecule.

Minsub Lee 3E

Both ionization energy and electronegativity increases as you move up and right of the periodic table. Electronegativity decreases as you go down the group because the increasing number of energy levels cause the outer electrons to be further away from the nucleus. Ionization energy increases as you...

Minsub Lee 3E

The double and triple bonds will not necessarily directly affect the bond angle. However, those bonds will most likely affect the molecular shape, which will affect the bond angles.

Minsub Lee 3E

For now, I do not think we need to. However, you should at least conceptually know that triple bonds are stronger and shorter than single bonds

Minsub Lee 3E

Going off of Melissa, the lone pair on the central atom wants to occupy as much space as they can, so they push the other atoms in the opposite direction, condensing the atoms to each other to make a see saw structure.

Minsub Lee 3E

I believe the average was an 83%.

Minsub Lee 3E

Thank you! This electronegativity graph is very useful!

Minsub Lee 3E

A single bond between two atoms is the longest and weakest while a triple bond is the shortest and strongest.

Minsub Lee 3E

By remembering the different shapes molecules can have, you can determine the shape by seeing the repulsion of the electrons and spreading the electrons as far apart as they can.

Minsub Lee 3E

They can have expanded valence shells because they have d-orbitals to accommodate additional electrons.

Minsub Lee 3E

The last two rows of the periodic table consist of the f-orbitals. By looking at the atomic number of those elements, you can see that they fit in the middle of the periodic table. It is the row after Xe

Minsub Lee 3E

I got a molar mass of 30g/mol as well. I believe that the calculations are right.

Minsub Lee 3E

To my understanding, I believe the midterm is closed notes and are unable to access any outside information.

Minsub Lee 3E

One is not more correct than the other. I think it is enough to understand that no electrons of the same atom has the same quantum numbers, and that an upper arrow symbol indicates that it is positive 1/2. They are just different in that they are spinning clockwise versus counterclockwise.

Minsub Lee 3E

Thank you so much! Transitioning into college has been tough, but this was very encouraging!

Minsub Lee 3E

You can also think of nodal planes mathematically as when the wave function (psi) is equal to 0. So when you draw out an ideal sin graph for n=1, the wave function is not equal to 0, and so there are no nodal planes for the principal quantum number n=1.

Minsub Lee 3E

As others said, nodal planes are areas without electrons. Through diagrams, it also helps to determine what kind of electron you are observing and what its energy level is. For example, if there were zero nodal planes, then it would be a s-block element, and have a principal quantum number n=1.

Minsub Lee 3E

Just a general tip is to remember the formulas and what you're trying to solve for. If you have to solve for kinetic energy, then you know you have to use velocity in the formula Kinetic Energy = 1/2mv^2

Minsub Lee 3E

I like to write it out like in dimensional analysis. It will help you follow your work, and you can clearly see what can be cancelled out. Since 1 Hertz is 1/s, if you multiply it with Jxs, the s will be cancelled out, leaving just s. I suggest writing out the units in your work for dimensional anal...

Minsub Lee 3E

Yes, use c=λv and e=hv to find the source. The correct unit for wavelength (λ) are meters.

Minsub Lee 3E

Actual yield should typically not be greater than the theoretical yield because theoretical yield is the maximum amount of product that could have been produced. However, there may be cases in your own personal experiment which may result in a higher actual yield than the theoretical yield, resultin...

Minsub Lee 3E

I will usually check to see which elements do not need balancing. Then I will start to balance the element that occurs the least. If adding a stoichiometric coefficient causes another element in that same molecule to be unbalanced, I would balance that. I usually just do that step-by-step.

Minsub Lee 3E

It will likely come up in the future. Dr. Lavelle mentioned that combustion, burning, or oxidation of organic molecules is the same as oxidative metabolism. They all release energy. This may be a key concept.

Minsub Lee 3E

Yes, you are able to submit questions from the sixth edition. On the syllabus, it will show the questions you need to answer for the sixth edition.

CHEMISTRY COMMUNITY

Search found 32 matches

Re: VSEPR in equal angles

Re: Bronsted vs Lewis

Re: Water as an Acid/Base

Re: calculating pH

Re: Bond Angles

Re: Weak Acid/Base vs. Strong

Re: Soapy Feels

Re: Naming Shapes

Re: VSEPR model

Re: The central atom

Re: bond angle

Re: Strength of Bonds

Re: See-Saw Shape

Re: midterm average

Re: Electronegativity Graph

Re: Bond lengths [ENDORSED]

Re: VSEPR

Re: Octet exceptions

Re: f- orbital

Re: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]

Re: Cheat sheet or open notes? [ENDORSED]

Re: Quantum Numbers related to Orbitals

Re: Advice from a Medical Student [ENDORSED]

Re: Nodal Plane

Re: Nodal Planes

Re: Friday 10/5 Lecture

Re: Units

Re: Problem 1A.9 (7th edition)

Re: Actual/Theoretical Yield

Re: Balancing reactions tips

Re: Combustion Analysis? [ENDORSED]

Re: Problem E7 converting atoms to moles