CHEMISTRY COMMUNITY

Linh Vo 2J

Can someone explain to me what order(s) correspond to what graphs? Positive slope, negative slope, decreasing sigmoid, zero order, first order, second order.

Linh Vo 2J

I don't think the textbook or Lavelle ever talked about its commonality in terms of ranks. I tried doing a Google Search too, but that just came up empty, so I don't think it's a concern we need to really understand.

Linh Vo 2J

To add, in discussion, my TA told me it's appropriate to use it when n=1.

Linh Vo 2J

Is it necessary for us to understand/know the ways how to derive the formulas? He showed us all the derivations in class, but I'm unsure if he would expect us to on a test.

Linh Vo 2J

When we talk about half-life, does this imply that there is normal life? I'm confused about what half-life is and when we would want to calculate it?

Linh Vo 2J

Can someone explain to me the difference between these three and what quantifies one to be a zero, first, or second reaction?

Linh Vo 2J

The rusting process equation is Fe+O2+H2O----> Fe2O3*H20. Refer to 7th edition 6N.21 problem for more clarification of it in practice. Basically, you need Fe (iron) plus H20 (water) plus O2 (oxygen) for the rusting process to be initiated.

Linh Vo 2J

When is it necessary to write the Pt(s) in the cell diagram?

Linh Vo 2J

In concentration cells, for example Ag(2)|Ag+(aq)||Ag+(aq)|Ag(s), when you take the standard reduction potential for the anode and cathode, the number will be the same. Thus when you subtract the same number by the same number, you will ultimately get E naught=0V.

Linh Vo 2J

Why does maximum potential occur when "very little current flows"? This is directly from the lecture, but I am confused what is the logic behind this.

Linh Vo 2J

Why does Gibbs free energy of a substance decrease (become less positive) as T increases at constant pressure?

Linh Vo 2J

Can someone explain to me why deltaG<0 is a forward process, deltaG>0 is a reverse process, and deltaG=0 is at physical equilibrium? What is the logic behind this?

Linh Vo 2J

where does the 3/2 come from? For heat capacities of ideal gases, we use Cv=3/2R for a monoatomic gas and Cv=5/2R for a diatomic gas such as N2 or H2. The constant being multiplied to R is determined by the greater number of degrees of freedom in diatomic as opposed to monoatomic gases, so 5/2 (dia...

Linh Vo 2J

Is internal energy (delta U) and the entropy in a system directly correlated? Like if internal energy is decreased, does the entropy decrease too? Or is there an inverse correlation between them?

Linh Vo 2J

In some questions, they state to assume ideal behavior. What does this mean? And will there be times where we have to assume it and the problem won't tell us?

Linh Vo 2J

How is the equation DeltaS=kBlnW used and what do the individual variables represent?

Linh Vo 2J

How do we calculate degeneracy? I'm not sure how to use the formula or its variables.

Linh Vo 2J

Is there a way to tell whether to use a reversible, isothermal equation or an irreversible equation to represent work?

Linh Vo 2J

Why are bond enthalpies of diatomic molecules accurate but using bond enthalpies is the least accurate method for all others?

Linh Vo 2J

Can someone explain “enthalpy changes are additive” to me and why this is so?

Linh Vo 2J

Can someone explain to me the three methods and when to use which?

Linh Vo 2J

No, I do not think he will be testing us on this concept even though it was lightly touched upon in our Chapter 12 homework.

Linh Vo 2J

The first statement is true because equilibrium reactions take account for both the reactants and products. If there is more products or reactants, the reaction will adjust accordingly according to the Le Chatelier's Principle. The second statement refers to its equilibrium CONSTANT, not reaction. F...

Linh Vo 2J

The value they are saying you need to approximate is the x (or value you are calculating) over that same number's initial value (given in the problem). The reason why we approximate to see if it's less than 5% is to verify if the approximation (aka the calculation we performed) was legitimate. We on...

Linh Vo 2J

I understand that volume and pressure are inversely related, I'm still a little confused about how this correlates with favoring the side with more moles? I think it is confusing to you because you have the idea wrong. When pressure is increased, volume decreases, and it favors the side with LESS m...

Linh Vo 2J

I think it would be based on the equilibrium constant. If products are favored, they are more stable. If reactants are favored, they are more stable. I agree with this. However, I think she meant to say that if products are favored, they are more stable. If reactants are favored, then they are less...

Linh Vo 2J

How do we use equilibrium constants to predict solubility?

Linh Vo 2J

To find Q, you would calculate it as if you were calculating K. So you would take the partial pressures of the reactants and products by placing the products/reactants (make sure to raise each product/reactant to its respective number). You would then solve for the answer and that's how you get Q.

Linh Vo 2J

What is Gibbs free energy and what do we need to know about its concept?

Linh Vo 2J

What is the difference between Q and K? What are their meanings?

Linh Vo 2J

HBr would have a larger dipole moment than HI since as Jamlah said, there's a greater electronegativity difference between H and Br than between H and I. In other words HBr is more polar and Bromine will attract electrons to itself more. I'm not understanding why HBr has a larger dipole moment than...

Linh Vo 2J

What is the difference between an acid and a SUPER acid? Same thing for a base and a SUPER base?

Linh Vo 2J

Ka is the acid ionization constant or equilibrium constant for chemical equations in weak acids with aqueous solutions. You would use the formula to determine the Ka based on the given information given for the molecule. It will not always be H and A, for there are other cases too.

Linh Vo 2J

Chelates do need to have a specific shape, cyclic or ring structure. For example, in an ethylenediamine-cadmium complex, a chelate ring occurs.

Linh Vo 2J

Are we going to be dealing with resonance structure and delocalized atoms on this Friday’s test? I do not believe we are going to have those questions because for my discussion, my TA said that the test will focus on VSEPR structures, bond angles, lone pair effect, and physical forces (Van Der Waal...

Linh Vo 2J

Hello, I was wondering to what extent we need to know about Lewis acids and bases. I know the basic information (eg. one shares and one donates), but I don’t know if that’s enough for the test. Can someone give me more information about their differences and similarities?

Linh Vo 2J

Can someone explain to me the cisplatin example we discussed in class again? I didn’t understand how the coordination compound structure contributed to stopping cell division.

Linh Vo 2J

The textbook in section 2.16 page 83 says, "Multiple bonds are shorter than single bonds between the same two elements because the additional bonding electrons attract the nuclei more strongly and pull the atoms closer together.” This should help clarify your question!

Linh Vo 2J

What is the reason why sigma bonds are stronger than pi bonds?

Linh Vo 2J

How can we determine if a compound is polar or nonpolar?

Linh Vo 2J

Hello, my TA told me that because the question was asking the bond length average, it would have been best to write the hybrid "average" of the bond lengths, which in that case 120+140/2=130. However, a range would have also been accepted because we are unable to pinpoint an exact number o...

Linh Vo 2J

Although polarizability and polarizing power sound similar, they are very different indeed and only share one relation: they are both related to the covalent character of ionic bonds, which means that the electrons slightly shared as opposed to being separated. Polarizing power is used to describe c...

Linh Vo 2J

I would like to add on that this also works vice-versa, which means that if you know the shape of the molecule or compound, you are able to figure out its bond pairs and lone pairs. Thus, the VSEPR model is ultimately very useful for deciphering both the molecular shape or the properties that the mo...

Linh Vo 2J

I'm not sure if everyone helped clarify your question, but something that really helped me grasp the concept of when I should take from the 4s and add to the 3d is when it helps the orbitals become either half-filled (3d^5) or fully filled (3d^10). The reason being is because half-filled and fully f...

Linh Vo 2J

Can someone explain what a work function is? I think i got that wrong on the test because i thought a work function was work as a function of time. Yes I can. Work function is basically the idea of the energy required to eject or emit an electron. In the equation, E(photon) = work function + E(kine...

Linh Vo 2J

If an element has a high electronegativity, does that mean it has higher electron affinity? I believe so because for one of our practice questions, the answer was something along the lines "If an element has a high ionization energy and a higher electron affinity, it is also highly electronega...

Linh Vo 2J

I agree with the previous posts in that theoretically, I believe you could form 9 bonds, but would be extremely unlikely since it deviates so far away from the desired charge of zero. By creating so many bonds, it would make the formal charge insanely high and unstable (since the best and most stabl...

Linh Vo 2J

I believe that it is always desirable to make the formal charge of a compound ultimately zero because it shows that a molecule is neutral, if we can. However, with the example compound you gave [SO4]-2, it is not possible to make the formal charge zero, thus we would have to strive to make the forma...

Linh Vo 2J

To sum up the ideas of this post and contribute to the discussion, to determine the central atom, there are multiple factors you can consider: 1. Which element is least frequently present in the compound? 2. Which one has the lowest ionization energy? 3. Which one is the least electronegative? The a...

Linh Vo 2J

does this include knowing the appearances of the orbitals like the d-orbital? To clarify, in my workshop today, my UA said that appearances of the orbitals would be useful to know and he might expect us to know the orbital shapes of s (circle-shaped), p (infinity sign-shaped), and d (four leaf clov...

Linh Vo 2J

To add on, "n" determines the energy and the size of the orbital. It is represented by integers like 1, 2, 3, 4, etc. "n" is important because it can help you determine possible values of l and m(l) because those quantum numbers are dependent on the value of "n".

Linh Vo 2J

We are not expected to calculate the probability of finding the electron at a particular location since we did not learn it in class.

Linh Vo 2J

To add on to the discussion, my UA told me today an analogy that I think would be really helpful! She said that increasing the intensity of a wavelength won't have an effect on the electron if there is not enough energy to eject an electron. Think of it like a hurdle. If the person attempting to jum...

Linh Vo 2J

I would like to add on that v in that case would be velocity because of the units correlation. However, you can also determine if it's velocity or frequency by the way it's written. v is often straight, while curly v represents frequency and often will use Hz or Hertz as units.

Linh Vo 2J

Hello! I was confused on this earlier too, but my UA clarified in my session that for this class, when you see v in terms of velocity, it will most likely be paired up with m (mass) in an equation or formula. Velocity is seen in the equations 1/2mv^2 and p=mv. While with the curly v, that would be c...

Linh Vo 2J

I was actually very confused about this myself recently, but I believe that the reason why long wavelengths cannot eject e- is because long wavelengths means smaller frequency. Frequency is related to energy and if there is small frequency, the energy is small too, thus meaning insufficient energy t...

Linh Vo 2J

Yes, there are ways to tell what color is presented by memorizing different wavelength ranges or using a chart. However, I feel that he does not expect us to be able to eyeball a wavelength and be able to determine its color.

Linh Vo 2J

Hello, I know that the notion that short wavelengths can eject e-, while long wavelengths cannot. However, I am unsure of the reasoning behind this and how this idea came about, so I would greatly appreciate it if someone helped explain this to me.

Linh Vo 2J

To add on to the discussion, I usually start the process of balancing the chemical equation by balancing the element that does not repeat or occurs the least. Then I try to balance the elements that are not common first and save the common ones, such as H or O for last.

Linh Vo 2J

To answer the above extended question of the difference between m and M, I believe that m represents the molar mass of an element, while M represents the molarity of the element.

Linh Vo 2J

It says to "calculate the molar mass of copper, given that a natural sample typically consists of 69.17% of copper-63, which has a molar mass of 62.94 g*mol^-1, and 30.83% copper-65, which has a molar mass of 64.93 g*mol^-1. (Note that the molar mass of an isotope is proportional to its atomic ...

Search found 61 matches