CHEMISTRY COMMUNITY

Emily Wang 1H

The answer says 2-isopropyl-1,1-dimethylcyclopentane. How do we know to use IUPAC or common naming? If we were to do IUPAC, would it be 1-methyl-2-ethyl-1,1-dimethyl-cyclopentane?

Emily Wang 1H

You use q=mCT when finding the heat of a particular substance with a mass, change in temp, and specific heat capacity. However when solving a problem with a bomb calorimeter, the mass is not necessary to solve for a value. A more specific notation would be q(calorimeter) = C(calorimeter)T

Emily Wang 1H

When naming substituents (whether they are alkyl groups or halogens), I think we are supposed to follow the alphabetical rule. The last two pages of this link explain it: https://www.utdallas.edu/~scortes/ochem/OChem1_Lecture/Class_Materials/07_org_nomenclature1.pdf.

Emily Wang 1H

For the IUPAC name, you get decane from the chain with 10 carbons. The 4 comes from the isopropyl group being attached to the 4th carbon from the left. You wouldn't start from the right because then it would be 6, and you always want the lowest number for IUPAC naming. Then, the 1 comes from the iso...

Emily Wang 1H

Catalysts aren't used up on the reaction, but they do show up in the overall rate law because the rate depends on their concentration.

Emily Wang 1H

It depends on the electrochemical series, which would probably be given. The higher up the element on the table, the more likely the element is able to be an oxidizing agent, or in other words, be reduced. To order the elements from most reducing to least reducing, you would list them in order from ...

Emily Wang 1H

You can use either log or ln and the answers will turn out to be the same. Just remember that ln is log base e. If you want to convert between the two, lnx = 2.303logx.

Emily Wang 1H

Yes, if there is no change in volume, then there is no work done by expansion because delta V will be 0.

Emily Wang 1H

An inert electrode basically acts as a sink for electrons while not actually taking part in the electrode reaction. In other words, inert means the electrode is not reactive. You would use an inert electrode if the reactant can't function as an electrode, but if you have a metal involved, it won't n...

Emily Wang 1H

E(nought) of the entire cell is the standard reduction potential, which is the difference between the two E values of each half reaction, so if you're multiplying by a number when the moles increase, the difference is still the same.

Emily Wang 1H

Both are the R constant and they are equal. The R value of 8.314 J/ K*mol value just converts L*atm into joules, by using the conversion factor of 1 L*atm = 101.32500 joules.

Emily Wang 1H

The reaction is exothermic because the temperature went up from 25C to 31.9C. This means the reaction released heat into the surrounding water in the calorimeter to heat it up, making it exothermic.

Emily Wang 1H

A problem involving a phase change will probably state it in the problem specifically, such as asking the energy needed to change solid water at a certain temp to gaseous steam at a certain temp.

Emily Wang 1H

We can find the number of moles of HCl given what the concentration and volume should have been. However the technician put it in a different volume, which would change the molarity. Now, we can find the pH of both since we can find out the concentration of both.

Emily Wang 1H

I don't think we need to know how to calculate changes in K based on changes in temperature for what we've learned so far. They just give us the temperature at that point for the K value.

Emily Wang 1H

Bar is a unit of pressure. It can be converted between atm, mmHg, Torr, and pascals to fit whatever the question is asking for.

Emily Wang 1H

Generally you would find the solution first assuming that x is negligible (less than 5% of your initial concentration), then see if the answer is actually less than 5% of whatever concentration you started out with. If it is, then your solution is viable; if not, you would have to redo the question ...

Emily Wang 1H

Both terms are describing properties of acids and bases, but amphiprotic is a bit more specific. Amphiprotic refers to a substance that can either gain or lose a proton, while amphoteric refers to a substance that can either be an acid or a base. However, there are multiple definitions for acids and...

Emily Wang 1H

They can be used interchangeably since they are both describing the equilibrium constant of acid dissociation.

Emily Wang 1H

The probability of an electron being at N or O depends on the polarity of the element. The more polar, the stronger the pull of the element on the shared electrons, so the higher the probability of an electron being there.

Emily Wang 1H

One example of a non-integer bond could be a molecule with two bonds, one of which is a double bond and the other a single. Then it'd be 3 divided by 2 and result in a bond order of 1.5.

Emily Wang 1H

When solving for oxidation numbers, there's a set of rules to follow first, which states that oxygen in a molecule will usually have an oxidation number of -2. So for Tl2O3 to be neutral overall, Tl will need to have an oxidation number of +3.

Emily Wang 1H

I think what you might've done is divide the grams of C, H, and O by 0.02939 moles. For example, if you convert 0.4942 g Carbon to moles, you get 0.04114904 moles C, and if you then divide that by 0.02939, you do get 1.4. The ratio comes out to be 1.4:1.2:1 once you convert grams to moles first befo...

Emily Wang 1H

The formal charge and oxidation number are two separate concepts. Formal charges are mainly calculated for structural purposes, such as drawing the most accurate Lewis structures, and do not actually denote charges on atoms in a molecule. On the other hand, the oxidation number of atoms tell us how ...

Emily Wang 1H

Yes, both notations are correct, it's just that the second one is more specific in that it specifies the orientation of the electrons of the p-orbital.

Emily Wang 1H

Since we're trying to find the energy of the electron, the mass used in the formula should be of an electron. 9.109 x 10^-31 kg is the mass of a single electron, and that number is just given to us since it is a constant.

CHEMISTRY COMMUNITY

Search found 26 matches

1.16 in ochem book

Re: q=mCT vs q=cT

Re: 2.16 Intro to Ochem chapter 2

Re: Quiz prep 3 question 1 [ENDORSED]

Re: Catalysts in rate law

Re: 14.85

Re: 2013 Midterm 8B

Re: Winter 2013 Midterm: Question #4

Re: Inert Electrodes

Re: Balancing reactions

Re: Quiz 1 || Question 3 || Which R?

Re: Example p. 20 of Course Reader

Re: Phase change

Re: Question 12.27

Re: Kw and temperature

Re: Bar [ENDORSED]

Re: 5 Percent Rule

Re: Difference between Amphoteric and Amphiprotic

Re: Acidity constants [ENDORSED]

Re: Molecular Orbitals of Different Metals

Re: Bond Order?

Re: Oxidation Number of Thallium in Tl2O3

Re: Mistake in the 2009 Midterm Solutions?

Re: Relation between Formal Charge and Oxidation Number

Re: Orbital Question [ENDORSED]

Re: Finding the kinetic energy of ejected electrons?