MARSHMALLOW- FINAL REVIEW SESSION  [ENDORSED]

Any general non-science questions (software questions/problems, etc.,) and class announcements.

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Sofia Barker 2C
Posts: 101
Joined: Wed Sep 18, 2019 12:21 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby Sofia Barker 2C » Sat Dec 07, 2019 11:39 pm

Kayla Maldonado 1A wrote:#16 why is the trigonal planar shape considered nonpolar, how did we determine this ?


Since it is given that all the "X" atoms are the same, the molecule will be nonpolar because any potential difference in charge between each atom X and the central atom will cancel out due to the symmetry of the molecule.

Anthony Hatashita 4H
Posts: 103
Joined: Wed Sep 18, 2019 12:21 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby Anthony Hatashita 4H » Sun Dec 08, 2019 12:06 am

how do you get 33b?

Jamie Hwang 2F
Posts: 104
Joined: Thu Jul 25, 2019 12:16 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby Jamie Hwang 2F » Sun Dec 08, 2019 1:21 am

Jingyao Chen 4H wrote:For number 41(c), it asks which pair of atoms on thymine are most tightly bounded and why, between C=C, C=O, and C=N. However, O don’t see a C=N bond in the structure. Is there a mistake?


I think there is a mistake on that but it doesn't matter because the answer is C=O because O is the smallest out compared to C and N.

Jamie Hwang 2F
Posts: 104
Joined: Thu Jul 25, 2019 12:16 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby Jamie Hwang 2F » Sun Dec 08, 2019 1:24 am

KBELTRAMI_4I wrote:For number 4 how does the hybridization become sp2 if there are 4 p electrons and 2 s electrons?


Hybridization is determined by electron densities around the central atom. Since S has three electron densities the hybridization is sp2.

Jamie Hwang 2F
Posts: 104
Joined: Thu Jul 25, 2019 12:16 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby Jamie Hwang 2F » Sun Dec 08, 2019 1:27 am

Paige Lee 1D wrote:For #1c on mini marshmallow, how do you know to choose NH4+ and not NO3- for the net ionic equation? Since they're both weak acids and bases


NO3- is the conjugate base of HNO3 which is a strong acid.

205150314
Posts: 106
Joined: Wed Feb 20, 2019 12:16 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby 205150314 » Sun Dec 08, 2019 2:19 am

Minimarshamllow, how do you know when a compound will make an acid or base?

205150314
Posts: 106
Joined: Wed Feb 20, 2019 12:16 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby 205150314 » Sun Dec 08, 2019 2:19 am

Final, does anyone know if the test will be evenly distributed or if it will focus more on items after the midterm

205150314
Posts: 106
Joined: Wed Feb 20, 2019 12:16 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby 205150314 » Sun Dec 08, 2019 2:20 am

How do we go about finding the shape for ligands ? how was c on minimarshamllow an octahedron ?

Diana Chavez-Carrillo 2L
Posts: 122
Joined: Fri Sep 28, 2018 12:18 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby Diana Chavez-Carrillo 2L » Sun Dec 08, 2019 8:52 am

Kayla Maldonado 1A wrote:#16 why is the trigonal planar shape considered nonpolar, how did we determine this ?


AX3 means that the central atom (A) will have 3 atoms attached to it (X3). This results in a trigonal planar shape. To determine its polarity usually if the attached atoms are all the same type of atom and the central atom has NO lone pairs then it will be nonpolar. The central atom in AX3 has no lone pairs so it is nonpolar. However, if it did then it would be written with an E like AX3E2 (E2 = 2 lone pairs on the CENTRAL ATOM). If the central atom has lone pairs then it will become polar.

Yuri Lin 4H
Posts: 51
Joined: Sat Aug 17, 2019 12:15 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby Yuri Lin 4H » Sun Dec 08, 2019 8:27 pm

my soul feels destroyed by the final exam

thank you UAs for all you've done for us this quarter and goodbye.

i am deceased.

Abigail Menchaca_1H
Posts: 104
Joined: Sat Sep 07, 2019 12:19 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby Abigail Menchaca_1H » Sun Dec 08, 2019 10:12 pm

For #17 on the marshmallow final, why is the pi bond composition for oxygen is O2p, C2sp2? I thought it only used the p orbital?

Varadhan_3G
Posts: 49
Joined: Wed Sep 18, 2019 12:20 am

Re: MARSHMALLOW- FINAL REVIEW SESSION

Postby Varadhan_3G » Mon Dec 09, 2019 1:12 am

In problem #21, why is the charge of the central Iron 2+? How do we interact with the surrounding N molecules, and what do the dotted bonds signify again? Thank you.


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