CHEMISTRY COMMUNITY

Mariah Guerrero 1J

Everything is fair game! Good luck everybody!

Mariah Guerrero 1J

"The name's bond. Sigma bond."
-007

Mariah Guerrero 1J

Did we cover this in class?

Mariah Guerrero 1J

Do we have to know the specific bond angles for certain molecular shapes. For example, would it be acceptable to say (on a test) that sulfite ion, SO3 2-, have bond angles less than 109.5? Are approximations ok to state?

Mariah Guerrero 1J

Square planar has four ligands and two lone pairs. A difference between the two is that the bond angles of the square planar shape are smaller than 109.5 because the atoms are pulled closer together by the repulsion of the lone pairs.

Mariah Guerrero 1J

Will we have to know this equation for the final? We haven't learned about it in lecture yet, right?

Mariah Guerrero 1J

So when determining if a molecule is ionic or covalent, it is not always/only dependent on the electronegativity difference? For example, MgI2 has a electronegativity difference of 1.3 (which is smaller than 1.67, the rule to be a covalent bond). However, MgI2 is an ionic bond right?

Mariah Guerrero 1J

So for electronegativity, we should be able to recall that it increases as you go across the periodic table and decreases as you go down the periodic table. The greater the difference in electronegativity, then greater ionic character the bond has.

Mariah Guerrero 1J

Is there a trend involved in the second ionization energy?

Mariah Guerrero 1J

Just to clarify, lowest energy means that the molecule has a formal charge of 0 (or close to 0), right?

Mariah Guerrero 1J

Yes! A - means that the molecule is an anion, meaning you ADD an electron. A + means the molecule is a cation, meaning you REMOVE an electron.

Mariah Guerrero 1J

Formal charge can be used to determine if a structure is stable. In drawing lewis structures for tests, the correct answer would be a lewis structure of a molecule with the formal charge of 0 (or close to zero).

Mariah Guerrero 1J

I would like to be part of the study group if one is organized!
My email is mariah.guerrero99@gmail.com

Mariah Guerrero 1J

I refreshed the page and the answer UV rays is still marked as incorrect.

Mariah Guerrero 1J

From my understanding, yes these terms are interchangeable. A charge determines the energy of an atom. Formal charge indicates a gain or loss of electrons while forming covalent bonds; thus, the charge determines energy gain or loss.

Mariah Guerrero 1J

So for our upcoming tests, the only acceptable lewis structures are those with a formal charge of 0?

Mariah Guerrero 1J

Can someone explain the difference between electron affinity and electron negativity again? I understand that both properties have the same periodic trend. Is there an easier way that I can remember the difference?

Mariah Guerrero 1J

Are there any trends that occur on the periodic table with cations and anions?

Mariah Guerrero 1J

In the simplest terms, ground state refers to an electron in its lowest energy and excited electrons refers to an electron that absorbs energy.
Here's a great video that goes into more detail of the difference! https://www.youtube.com/watch?v=62ll5Tt_3zY
Hope this helps!

Mariah Guerrero 1J

Hello! I am working on n the post-module for the audio-visual focus topics and this question came up: In photoelectric experiments, typically what part of the electromagnetic spectrum is the incoming light? A. Ultraviolet B. Infrared C. Visible light D. Gamma rays E. None of the above I assumed the ...

Mariah Guerrero 1J

Electrons have diffraction patterns that result from constructive or destructive interference. How does this relate to De Broglie's equation?

Mariah Guerrero 1J

You can use Rydberg's Equation to solve for the energy levels (n). E= -hR/n^2
If the energy is given in the problem, you would simply have to rearrange the equation in terms of n as it is the only unknown in this case.

Mariah Guerrero 1J

If energies (E photon and work function) are given in the problem or you can solve for them, then you do not need to use the KE equation. Subtract the work function (also called the threshold energy or ionization energy) from E photon to find the KE. However, if only KE is asked with no other inform...

Mariah Guerrero 1J

I think the problems listed from chapter one will not all be on the test; some of these problems are similar to one another. The most important thing for us to do with these problems is to understand the concepts and be able to apply those concepts any which way that is asked.

Mariah Guerrero 1J

Hello all!
I cannot seem to find the post Dr. Lavelle created that states the specific chapter problems we should focus on for test 2. (He showed us the post at the beginning of class on Wednesday.) Can someone help me locate the info?

Mariah Guerrero 1J

I would be interested in joining a study group as well! Let me know if one is created please! My email is mariah.guerrero99@gmail.com!

Mariah Guerrero 1J

Question 1.5 states to arrange the following types of photons of electromagnetic radiation in order of increasing energy y rays, visible light, ultraviolet radiation, microwaves, x rays. I understand the order of increasing energy is y ray, x ray, ultraviolet, visible, infrared, microwave and radio....

Mariah Guerrero 1J

Combustion refers to the burning of air, with a reaction with molecular oxygen. Therefore, to start off by writing the correct chemical equation you would write KCl + O2= . Writing the reactants as one (letter B) creates a new, separate molecule that will produce a different outcome. KCl reacts with...

Mariah Guerrero 1J

An extensive property is a property that does depend on the size or the "extent" of the sample. In this case, mass and density are an extensive properties. An intensive property is independent of the size of the sample. Volume and temperature are examples of extensive properties.

Mariah Guerrero 1J

What is the difference between reagent and reactant? Or are these terms interchangeable?

Mariah Guerrero 1J

Can a reaction have two limiting reactants?

Mariah Guerrero 1J

I am reviewing the post-assessment for the audio-visual focus-topic for limiting reactants, and I am stuck on this problem. According to the following equation, 0.750 g of C6H9Cl3 is mixed with 1.000 kg of AgNO3 in a flask of water. A white solid, AgCl, completely precipitates out. What is the mass ...

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Re: Final Exam [ENDORSED]

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