CHEMISTRY COMMUNITY

Katherine_Zhuo_3B

For cycloalkanes,You look at the numbering for the lowest number on substituents, and if they are equal, you number based on first named.

Katherine_Zhuo_3B

When naming the double and triple bonds, you number the bond based on which carbon it starts on.

Katherine_Zhuo_3B

I believe the prefix iso- is not restricted to 4 or less carbons, and you can tell when it is used when the line structure has a branch of CH(CH3)2

Katherine_Zhuo_3B

The potential energy profile is generally used by physical chemist's and refer to activation energy, while the free energy profile is generally used by organic chemists.

Katherine_Zhuo_3B

I believe that entropy is less negative because by putting the molecules in the correct order and orientation, there is greater facilitation to the reaction occurring, which leads to more entropy.

Katherine_Zhuo_3B

For zero and first order reactions, the slope = -k. For second order reactions, the slope = +k.

Katherine_Zhuo_3B

For n, the moles of e-, does it have a unit, or is it just the number. For example, in deltaG=-nFE, if F is C/mol and E is J/C, is the n units mol so that delta G is J or is does the n have no units so that delta G =J/mol?

Katherine_Zhuo_3B

General polyatomic ions such as NO3-, SO42-, will need to be known, as well as common charges such as O2-, H1+, and 1+ charges for alkali metals.

Katherine_Zhuo_3B

Since the change in entropy is equated by q/T, as T increases, the overall change in entropy is decreasing if the heat (q) remains the same.

Katherine_Zhuo_3B

U stands for internal energy, and delta U stands for the change in internal energy, which can be calculated by delta U = q + w. G is for Gibbs Free Energy, and delta G stands for the change in free energy of a system, which can help determine the spontaneity and favorability of a reaction. There are...

Katherine_Zhuo_3B

Generally, the standard enthalpy of formation is in kJ/mol, and for the standard enthalpy of reaction, answers are generally kJ. You can determine the kJ/mol for standard enthalpy of reaction by looking at the chemical equation.

Katherine_Zhuo_3B

In a reaction, anytime a bond is formed, it is an exothermic reaction. This is because energy is released when the bonds are formed. To express that the reaction is exothermic, the delta H is negative. In a perfect system where qsys =- qsurr, this equation is derived from the 1st Law of Thermodynami...

Katherine_Zhuo_3B

So looking at NH4Cl, we have the cation NH4+ and anion Cl-. In a solution, the concentration of Cl- does not change, nor does it affect the pH of the solution. However, NH4+ is a weak acid, and so it will want to react with the water molecules to form NH3 (the more stable molecular form), and H3O+.

Katherine_Zhuo_3B

Given NH3 (aq), by memorizing the strong/weak acids and bases, we know that NH3 is a weak base. The lone pair on the nitrogen will bond with neighboring hydrogens from the H2O to form conjugate acid NH4+ and conjugate base OH-.

Katherine_Zhuo_3B

Q is the reaction quotient, which measures which direction a reaction will proceed given the initial partial pressures or concentrations. K is the equilibrium constant, which is a ration of products to reactants that does not change for the same reactions under the same conditions.

Katherine_Zhuo_3B

For the formula, as long as you put the transition metal first, the ligands can be put in any order following the metal.

Katherine_Zhuo_3B

An example would be the one we saw in class, where cis-diamminedichloroplatinum has the chlorides both on the left, whereas the trans-diamminedichloroplatinum has the chlorides located on opposite sides of each other.

Katherine_Zhuo_3B

The principal quantum number is an integer that describes the energy level of the electron. As n increases, the number of electronic shells increases and the electron is further from the nucleus and therefore has a higher energy. To compute n, we can utilize Rydberg's equation given the energy: En=-...

Katherine_Zhuo_3B

With the arrow showing us the delta positive pole and delta negative pole, we can determine which atom in the molecule has a higher electronegativity than the other, and will pull the shared electrons closer when sharing.

Katherine_Zhuo_3B

Elements that are exceptions to the octet rule include P, S, Cl. This is because they are located in period 3 on the periodic table, meaning that they have l= 0,1,2. This corresponds to the s, p, and d orbitals. Hence, in their valence shell, they have d-orbitals that can accomadate additional e-. T...

Katherine_Zhuo_3B

In fact, all matter has wavelike properties. However, only those with small mass and high velocity have wavelike properties that could be detected. For everyday objects such as baseballs, it is difficult to detect the wavelike properties.

Katherine_Zhuo_3B

When the energy of a photon matches the energy difference between quantum levels, (which are represented by the lines shown in the model below), electrons will get excited and move to the next level. The arrows are pointing downwards as the model is showing the emission of energy as electrons return...

Katherine_Zhuo_3B

Yes, if there is a decimal, you would count the non-zero digits as sig figs. For example, 300. would be 3 sig figs. In cases such as numbers like 0.00500 however, since the preceding zeroes are simply place holders to put decimals in the correct location, the only numbers that are counted as sig fig...

CHEMISTRY COMMUNITY

Search found 23 matches

Re: Cyclo-

Re: Naming what carbon the double/triple bond is on?

Re: Iso and Neo Prefixes

Re: Types of energy profiles

Re: Catalysts and Entropy

Re: Slope of k

Re: how to calculate n correctly

Re: Balancing equations

Re: Change in entropy= q/T [ENDORSED]

Re: Gibbs v internal

Re: kJ vs. kJ/mol [ENDORSED]

Re: Specific heat capacity [ENDORSED]

Re: Identifying a salt

Re: How to determine which is an acid and which is a base?

Re: Reaction Quotient Less than or Greater than 1 [ENDORSED]

Re: Alphabetizing Ligands

Re: Trans and Cis

Re: Balmer and Lyman Series [ENDORSED]

Re: Dipole Moment in a Lewis Structure

Re: The Octet

Re: Neutrons

Re: Energy Level Model [ENDORSED]

Re: Easy Way to Calculate Sigfigs