CHEMISTRY COMMUNITY

Chels Zh 1D

As we know that HCl is a strong acid and because chlorine is high electronegativity, so that the higher electronegativity an ion is, the stronger its acid, why is this true?

Chels Zh 1D

What is the relationship between pKa and the acid strength, and the relationship between pKb and the basic strength?

I have trouble understanding this explanation in the answer-key book.

Thanks, someone who can help me explain it!! :))

Chels Zh 1D

For example, why Cl- is a conjugate base of HCl?

Chels Zh 1D

I don't really understand the three equations of H2CO3+H2O in the end of this page, either.

What does it mean by," because harder to lose H+ from negatively charged ion(HCO3-)?"

Chels Zh 1D

Generally speaking, salts are the products of acids and bases, an ionic compound composing of cation and anion.

Chels Zh 1D

I am confused about the bold NOTE in the end of the course reader on page 156, saying that:
"if [H3O+] <10^-7, then solution is considered neutral because we know that autoprotolysis generates 10^-7 mol/L H3O+"

Chels Zh 1D

Can someone please explain a base's conjugate acid and an acid's conjugate base to me? I am very confused with this relationship.

Chels Zh 1D

Hi there, :) I found this VSEPR chart online, which seems pretty useful to me, hope this could help you guys too!

http://web.gccaz.edu/~kimld88531/vsepr%20handout.pdf

Chels Zh 1D

It is Square Pyramidal.

Chels Zh 1D

Is it true that Hydrogen, H is always likely to attach to oxygen O atoms in a Lewis structure? :) For example, one homework problem from chapter 3. 57 (B), the Lewis structure of HSO3-, H restricts the electrons to the oxygen atom rather than to sulfur atom. Does it apply to all of the hydrogen atom...

Chels Zh 1D

Is it true that covalent bond only holds TWO nonmetal atoms together by sharing electrons?

Chels Zh 1D

Reading the solution of Q57, for sulfite ion, SO3 2-, since both the structure followed the octet rule and the structure with expanded octet have the equal charge, what does it mean by "the structures with expanded octets have lower formal charges"?

Chels Zh 1D

What is the relationship between the sum of the formal charge of each atom in a covalent bond, and the charge of the compound itself? I found some practice shown that they are equal, is this a coincidence or it is the correct relationship. -:)

Chels Zh 1D

Does it matter where the dots are in a Lewis structure? For example, for Mg, both the textbook and course reader write it as Mg: , while when I looked it up online, it is written in a different way, like :Mg , does it matter where the dots are placed? Or is there a specific rule to follow when writi...

Chels Zh 1D

Thanks a lot! :))))

Chels Zh 1D

As I have been confused for a while, what is the correct electron configuration for Cu, and furthermore for its ion, Cu+, and Cu2+? Should we write it the way putting 4s ahead of 3d or not? I would highly appreciate someone if they may explain it.

Chels Zh 1D

: 954cb361299dbf962caaba2829ce6bd1--science-puns-chemistry-puns.jpg (10.42 KiB) Viewed 15989 times

Cation has positive charge
Cat has paws (^._.^)ﾉ

Chels Zh 1D

Hi, there, I happen to find a previous post that explained this question, see link below. Hope it helps!:)
viewtopic.php?t=5876

Chels Zh 1D

Nahal 1F wrote:How do you find the number of unpaired electrons for the ground state configuration of:

a)Pb
b)IR
c)Y
d)Cd

Man this is the question 52:))))))))

Chels Zh 1D

I am still confused while I checked the chart in course reader page 70, it shows that carbon has an energy of +122kJ/mol, while nitrogen has an energy of -7kJ/mol. But why is it true according to the trend of electron affinity?

Chels Zh 1D

sandraabdelmalak1D wrote:There are 3 subshells in the shell where n=3.
The number of types of subshells is the same as the shell number.
The first shell has one type of subshell (s)
The second shell has two types of subshells (s, p)
The third shell has three types of subshells (s, p, d).

Thanks!!

Chels Zh 1D

How many subshells are there in the shell with n=3?
How to solve problems like this? I looked up the answer but I don't know how to get it. Thanks!!! :)))

Chels Zh 1D

Thanks, guys! :)))

Chels Zh 1D

For step (a), I would like to go with to assume there are 100g of the sample, I got the ratio is 4:4:1 of C:O:Os. Then I got the empirical formula OsC4O4. Then at (b) we can calculate the molar mass of the empirical formula, which is 302.24 g/mol, divided this number by 907 g/mol, which gives us a n...

Chels Zh 1D

Does someone know that from which page to which page in the course reader is covered in Exam 1 on Wednesday?

Chels Zh 1D

Hey guys, how did you get no.5, I got an extremely small number, I think I might have got some steps wrong.

Chels Zh 1D

[attachment=0]IMG_0432.JPG[/attachment]

Chels Zh 1D

I believe the mass of an electron is a constant that we don't need to calculate, and I think it will be provided for us in the test.

Chels Zh 1D

Hi, there, here is what I got

And thanks for telling me where the self-test is!
Hope this would help!

Chels Zh 1D

Same... I have calculus lecture colliding with today's review section.

Chels Zh 1D

Could you type the full question please, and by the way, where can I find the self-test?

Chels Zh 1D

The energy of an atom is increased when electromagnetic radiation is emitted from it?

Chels Zh 1D

Thank you so much!!!!!!!! I understand it clearly now.

Chels Zh 1D

When I was going through the summary part of the photoelectric experiment, I have a couple of unclear concepts.
The first point said that "light not acting like a classical wave", so what role does it act? As photons or particles?
Does high intensity mean the light beam with more photons?

Chels Zh 1D

[quote="Gwyndolyn"]The formula sheet gives the mass of an electron as 9.1095 x 10^-31 kg, so I think you would just use this.[/quote]

Thanks! I greatly appreciate that :)

Chels Zh 1D

Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. Answer the following three questions. A. What is the kinetic energy of the ejected electron? For this question, we should use the equation of kinetic energy...

Chels Zh 1D

When the energy per photon is equal to the energy required to remove an electron what is this energy called?
A. Binding energy

B. Threshold energy

C. Transition energy

D. Excitation energy
My answer is A. Binding energy, but it showed me wrong, what is the correct answer?

Chels Zh 1D

Hi there, it's not a problem of using whether one giant step or breaking up into small parts, I feel like it is just personal preferences, for me, I like to classify the same type together on the same side, getting easier to visualize. And for instance, it is always useful to use the SI units as the...

Chels Zh 1D

Question extension:
What does a blackbody specifically mean in the speaking of photons and spectrum?
Does it apply to any light source or it just implies to the sun, which Dr. Lavelle mentioned in class?

Chels Zh 1D

Hi there, just got a quick thought of what you may concern: I will follow up the steps next, since you've already got to 0.1112, which is the frequency we need for n1, and by using Rydberg equation we can solve for n2: v=R(1/n1^2-1/n2^2), from that equation, we have known that constant R = 3.29E15, ...

Chels Zh 1D

From my experience of balancing equations, I always adjust the metals first, nonmetals last. Because metals are usually the kinds of elements has the least amount of atoms, existing in a formula unit, compounding with other nonmetals. Like the previous person said, I like to leave H & O at the v...

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