CHEMISTRY COMMUNITY

Heerali Patel 3A

I believe amide functional groups are usually located on the end of the carbon chain such that they can be labelled the carbon atom one.

Yes, an amide functional group has one carbon with a double bond to an oxygen and two single bonds, one of which is to a nitrogen.

Heerali Patel 3A

Yes, you must always start counting from the same side when numbering.

Heerali Patel 3A

I believe the prefixes iso- and neo- have Greek origins in which iso- comes from the word isos, meaning equal, neo- comes from the word neos, meaning new. Tert- (tertiary) comes from the Latin word tertarius, meaning third/third part.

Heerali Patel 3A

Since it's relevant to Wednesday's lecture...

Heerali Patel 3A

The units of k should tell you what the order of the reaction is. You can then find the rate law of the reaction and use the given info. to solve for the (initial) concentration of the species. The question asks for initial amount in grams so you can then use the given info. to convert this concentr...

Heerali Patel 3A

Question 8.51: The enthalpy of formation of trinitrotoluene (TNT) is -67KJ/mol, and the density of TNT is 1.65 g/cm^3. In principle, it could be used as a rocket fuel, with the gases resulting from its decomposition streaming out of the rocket to give the required thrust. In practice, of course, it ...

Heerali Patel 3A

I believe the equation should be lnK=(nFE)/(RT), which includes the number of moles.

Heerali Patel 3A

A salt bridge maintains electrical neutrality (charge balance) so the cell does not run the reaction to equilibrium very rapidly. In addition, from page 573 in the textbook, the salt bridge also keeps the solutions from mixing and usually consists of a gel with a concentrated aqueous salt solution i...

Heerali Patel 3A

Heerali Patel 3A

Yes. Essentially, reactants are the molecules whose bonds are broken, and products are the molecules whose bonds are formed.

Heerali Patel 3A

I believe, in general, the final temperature and respective equilibrium constant are used as T2 and K2 and the initial temperature and respective equilibrium constant as T1 and K1.

Heerali Patel 3A

Yes, you are correct. When delta S and delta H are both positive, a spontaneous reaction can only occur at high temperatures because this is the only way T*delta S will remain higher (in value) than delta H, such that delta G will be negative and the reaction will be spontaneous. Similarly, when bot...

Heerali Patel 3A

Camryn Marshall 1C wrote:How would we have known this without seeing it in the solutions manual? Is it listed somewhere in the textbook?

Yes! It is discussed in Section 8.10, specifically on page 281.

Heerali Patel 3A

For Standard Enthalpy of Formation and Bond Enthalpy values, units will be in kJ/mol, however, these values are used to find the Standard Enthalpy of Reaction which will be in units of kJ. With Hess's Law, on the other hand, the reaction enthalpies used in each step and the overall reaction enthalpi...

Heerali Patel 3A

Water can also phase change through sublimation. For example (from the textbook on page 285), frost formed from cold, dry mornings disappears when the ice sublimes into water vapor.

Heerali Patel 3A

Generally, salts that contain cations from groups 1 and 2 (e.g. NaCl) do not affect pH because these cations are weak lewis acids. Additionally, acidic salts (e.g. NH4Cl) will lower the pH of a solution because of the acid (NH4+ of NH4Cl) reacting with water to form H3O+, but the anion (the halogen ...

Heerali Patel 3A

pKa1 and pKa2 are the negative logs of the acidity constants for the first and second stage in which a polyprotic acid loses a proton. pKa(overall) is the negative log of the overall acidity constant for the overall ionization reaction of the polyprotic acid. For example, using H2CO3 as the polyprot...

Heerali Patel 3A

Essentially, the answer for 3b is only equivalent to the threshold energy because the problem only tells you the minimum frequency and asks for the threshold energy. This disregards the kinetic energy given for 3a since 3b only asks for threshold energy, not energy of a photon, which does not requir...

Heerali Patel 3A

When given the formula of the compound, the name is written with ligands in alphabetical order. If you are given the name and have to write the formula, usually the order is [Transition Metal...Anionic Ligand...Neutral Ligand]^charge, also keeping the ligands in alphabetical order.

Heerali Patel 3A

The alphabetical rules applies when naming the compound. For example, if [Ni(NH3)5Cl]Cl2 were given, the answer is pentaaminechloronickel (III) chloride in which the ligands are placed in alphabetical order. However, for questions where the name is given and the formula is to be found, the order is ...

Heerali Patel 3A

The difference is that for any atom with atomic number, Z, less than 8, the MO diagram will have the sigma(pz) orbital at a higher energy than the pi(px) and pi(py) orbitals due to electron-electron repulsion. For any atom with Z greater than or equal to 8, the MO diagram will be the opposite, meani...

Heerali Patel 3A

This electron configuration represents the excited state of an iodine atom. You can tell because the ground state configuration would have a full 5p orbital (6 electrons) and zero unpaired electrons, given this is the lowest energy state possible for iodine. In this case, one valence electron has mo...

Heerali Patel 3A

Technically, the hydrogen can be attached to the double-bonded oxygen, but it is preferable to attach it to the single-bonded oxygen because this gives a formal charge of zero for that oxygen. The hydrogen bonded to the double-bonded oxygen gives that oxygen a formal charge of -1, however, a zero fo...

Heerali Patel 3A

Although Tungsten is located in the 6th group and the 6th period on the periodic table, the f-block begins in the 4th shell. This means that the electron configuration for Tungsten will contain the 4th shell of the f orbital, labelled 4f.

Heerali Patel 3A

The second electron that would be removed is generally closer to the nucleus of an atom. For this reason, it has a stronger pull acting upon it by the nucleus than the first electron does. This stronger pull makes removing the second electron harder.

Heerali Patel 3A

Usually, with multi-step problems, you only round for the final answer to avoid the slight differences that occur in the answers if you were to round with every calculation. This also helps with getting a greater accuracy regarding theoretical yields and actual yields.

CHEMISTRY COMMUNITY

Search found 26 matches

Re: Amides

Re: Quiz prep 1 #3

Re: Common Name Origins

Re: Chemistry Jokes

Re: Calculating Initial Amount given Rate and k

Question 8.51: positive vs. negative enthalpy

Re: ln K equation

Re: Purpose of Salt Bridge

Re: Chemistry Jokes

Re: Bond Enthalpies

Re: Van't Hoff equation question

Re: Spontaneity of Reactions

Re: 3/2 and 5/2 R

Re: units of hess's law, bond enthalpy, standard enthalpy

Re: Sublimation in Action

Re: pH change

Re: pKa v. pKa1 and pKa2

Re: equations for the photoelectric effect

Re: Naming Order

Re: Pentaaminechloronickel (lll) chloride.

Re: MO Diagram Rules

Re: Energy State

Re: Homework 3.57b

Re: #43 e) homework question: electron configuration tungste

Re: Removing 2nd Electron

Re: Exact numbers in the final answers