ASHLEY'S STEP UP WORKSHEETS

[Chem_Mod]

Hello everyone! My name is Ashley, and I am one of your UA's this summer. I will be hosting my Step Up sessions on Mondays, where I will be going over each problem step by step. I will mostly be pulling problems from the listed homework assignments, and I will also be posting the answer key online. If you want the step-by-step methods on how to approach the problems, come to the Step Up sessions!!!

Attached is this week's Step Up Worksheet. Hope to see you there!

[Chem_Mod]

Here are the answers for the first worksheet!

[Chem_Mod]

Hello Everyone! I hope everyone had a great Fourth of July, and are now soon preparing for your midterm next week! Attached is the worksheet that I will be going over in my session on Monday. It includes problems that would be similar to what you may see on your midterm. Happy studies!

[Jeril Joseph 1B]

Here are the answers for the first worksheet!

I had a question on number 3 on this worksheet. So, I got up to getting 4.74 x10^39 s.^-1 mol. ^-1, but I don't know what to do from there. I attempted using stoichiometry to convert my units, but I don't know what to use to do that. Can someone help????

[Jeril Joseph 1B]

Also, for the last question on the worksheet, shouldn't it be 10^15 since you're doing -18 - (-34)???? I got the other part of the answer, but is there an error with the exponent or is it just me?

[Chem_Mod]

Yes, you are right that it should be 3.08 x 10^15. My apologies on the typo in the answer key!

[Chem_Mod]

Here are the answers for the first worksheet!

I had a question on number 3 on this worksheet. So, I got up to getting 4.74 x10^39 s.^-1 mol. ^-1, but I don't know what to do from there. I attempted using stoichiometry to convert my units, but I don't know what to use to do that. Can someone help????

For number 3, the problem tells you the threshold energy required to remove an electron and we are trying to find the shortest frequency of light required to remove it (thus the minimum amount of energy without having the electron being released with any kinetic energy). We can therefore use E = hv and use the given threshold energy (3.14x10^3 kJ/mol) as E and solve for v.

If you pay attention to the units, it is given in kJ/mol, but we actually want J/photon because we want the amount of energy to remove a single electron from the energy of a single photon. Therefore, using stoichiometry to convert kJ/mol to J/photon, we get:

(3.14*10^3 kJ/mole photons) x (10^3 J/1 kJ) x (1 mole photons/ 6.022*10^23 photon) = 5.21*10^-18 J/photon

Now we can plug in 5.21*10^-18 J/photon into the E = hv equation and solve for v.

Hope this helped!

[Jeril Joseph 1B]

This was helpful. Thank you so much!

[Chem_Mod]

I have attached the answers to the worksheet, including some step-by-step calculations.

[Chem_Mod]

Here is the worksheet for my Step Up session this upcoming Monday. Feel free to take a look at it if you get the chance. If not, we will go over the questions step-by-step.

[Chem_Mod]

Answers to the last worksheet

[Jeril Joseph 1B]

Answers to the last worksheet

Question: On 2c, wouldn't the answer be CO2 since there is a larger electronegativity difference. Because you said CS2 has more covalent character when the questions asks for a greater ionic character.

[Chem_Mod]

Good catch! Yes you are right, CO2 would have more ionic character. C and S have very similar electronegativity, so CS2 would be more covalent.

[Chem_Mod]

Step up worksheet for this Monday

[Jeril Joseph 1B]

Step up worksheet for this Monday

Question: For 1b, is there supposed to be a charge because I'm having trouble drawing the structure of CH2F as being neutral. Or is the molecule a radical?

[Chem_Mod]

Answers for this last week. And you always find my one typo! Sorry, 1b was meant to just be CH3F, not CH2F.