CHEMISTRY COMMUNITY

Nicholas Carpo 1L

H-bonding is generally the strongest because there is a high electronegative difference between the partially positive H and N, O or F which have high electronegativity values.

Nicholas Carpo 1L

For determining relative acid strength (ie comparing which acid is stronger), electronegativity can help you determine which acid is stronger. The general guideline is that when looking at the conjugate bases of two acids, the molecule that has more electronegative atoms is the result of a stronger ...

Nicholas Carpo 1L

You can determine relative acid strength based on two main factors: 1. bond length in relation to the acidic proton (longer bond, stronger acid) 2. resulting anion stability (more stable conjugate base, stronger acid) But to differentiate strong acids vs weak acids, usually you have to just memorize...

Nicholas Carpo 1L

For this question, it asks if the reaction is between a Bronsted acid and base.

(c)CH3COOH + NH3 -> CH3CONH2 + H2O

The answer in the solution says that there is no proton transferred. Can someone explain what's happening and why there isn't?

Nicholas Carpo 1L

Yes the lone pairs are taken into account since the number of hybrid orbitals is equal to the number of regions of e- density around the atom.

Nicholas Carpo 1L

Yes they have similar trends. Both increase as you move right across a period and up a group/family.

Nicholas Carpo 1L

The polarizability of anions increases as the ion gets larger and less electronegative.

Meanwhile, the polarizing power of cations increases as the ion gets smaller and more highly charged.

Nicholas Carpo 1L

Hi so I still don't really understand the importance of coordination compounds and what exactly ligands do. If someone could explain them to me that would be great! Thanks!

Nicholas Carpo 1L

Can someone please explain the difference between e- promotion and hybridization? Thanks!

Nicholas Carpo 1L

The s-character is how much the sigma bond contributes to the hybridization.

For example, sp3 orbitals have 25% s-character and 75% p-character, while sp orbitals have 50% s-character and 50% p-character.

Nicholas Carpo 1L

It matters when you are drawing the 3D structure and determining the molecular geometry of the molecule. Since the lone pair would want to be in the area where it interacts with the least amount of other atoms, it would be in the equatorial plane with the 2 F atoms, while the 2 O atoms will be on th...

Nicholas Carpo 1L

Molecules have the see-saw shape if they have the AX4E VSEPR notation which means they have 4 bonding pairs and 1 lone pair around the central atom.

Nicholas Carpo 1L

To determine if there is a lone pair, you would generally look at the angles between atoms. If there is a smaller bond angle than expected, there must be electron repulsion resulting from lone pairs. However, lone pair repulsion could also cancel each other out, so you should base it on the placemen...

Nicholas Carpo 1L

Although we probably won't be asked to draw molecules in 3D, it definitely helps to know how the atoms would be arranged in a three-dimensional space to determine things such as polarity and shape.

Nicholas Carpo 1L

If a molecule has H-atoms does that mean there is always H-bonds as intermolecular forces? Are there any exceptions?

Nicholas Carpo 1L

To determine dipole moment, you would normally base it upon the forces present within the molecule and between molecules. So, the larger the difference in electronegativity, the larger the net dipole moment. For example, ionic bonds have higher dipole while covalent bonds do not.

Nicholas Carpo 1L

To determine, the shape (molecular geometry) of a molecule, you would have to consider the number of electron groups which comprises of both bonding pairs and lone pairs.

Nicholas Carpo 1L

A Lewis Base is a species that donate e- pairs (ie. NH3, F-, OH-). While, a Lewis Acid is one that accepts e- pairs (ie. BF3, H+).

Nicholas Carpo 1L

Cations are smaller because since they have less electrons than their parent atoms, they are pulled in more closely by the protons (which are unchanged) in the nucleus. The opposite goes for anions where they have increased electron repulsion.

Nicholas Carpo 1L

Usually, to calculate the energy of an (ejected) electron, you would need to know the velocity using the equation mv^2 / 2. So, I do not think that you would be asked to calculate the energy when you are only given the wavelength. The equation E=hv is meant for calculations pertaining to light (and ...

Nicholas Carpo 1L

During today's lecture, there was a slide that said "Highly distorted electrons are described as being highly polarizable." Can someone please explain what this means? And also how do you know if the electrons are highly distorted? Thanks!

Nicholas Carpo 1L

I think it also has to do with the fact that the atomic numbers of 3d are larger than 4s so it would make more sense if they would be arranged after it, on the same row.

ie. Sc (which has a 3d orbital) has 21 protons or electrons while Ca (which only has up to 4s) has 20 protons or electrons.

Nicholas Carpo 1L

In the case of covalent bonds, since the shared electrons help satisfy its electrons needs (or the octet guideline), those electrons are also attracted to the nuclei of the other atom, keeping it more stable.

Nicholas Carpo 1L

The derivation of the Spin Quantum Number is based upon the Pauli Exclusion Principle. So, although the spin number is not part of the Wave Function, it helps completely specify an e- in an atom particularly spin state.

Nicholas Carpo 1L

In calculating uncertainty in momentum, you would normally use the value for diameter. But in the example you gave, they gave a specific section of the atom wherein the position of an electron could be found. So you would use the given (which is 1% of radius) to calculate the uncertainty in position...

Nicholas Carpo 1L

I saw that in a few numbers in the textbook practice problems ask for the type of wave that corresponds with the wavelength/frequency you solved. I was just wondering if there is a strict range (ie. 400-700nm) for each wave type on the electromagnetic spectrum. Thanks!

Nicholas Carpo 1L

Because this problem states that the given values produced occur "in each second", the value for watts and joules would be the same (aside from the difference in units).

Nicholas Carpo 1L

I know that the rule for significant figures for adding numbers is to follow the least amount of decimal places. However, I was wondering how that would work for numbers in scientific notation. Ex. In adding 1.11 x 10^-9 and 1.1 x 10^-10, since they virtually have the same amount of decimal places w...

Nicholas Carpo 1L

For this you would use the equation relating the speed of light to wavelength and frequency [ c = λv ] to first solve for the frequency. Afterwards, you could use the Rydberg equation [ v = R ( 1/n1^2 - 1/n2^2 ) ] to solve for the final energy level.

Nicholas Carpo 1L

Using the equations E=hv and c=λv, you can derive the equation E = hc/λ which solves for the amount of energy emitted by one atom when it generates a photon. You know the values of λ = 589nm or 589 x 10^-9m as well as the constants h (Planck's constant) and c (speed of light). So for (a): E = hc/λ E...

Nicholas Carpo 1L

Intensity can be measured by W/m^2 (watts per square meter).

Nicholas Carpo 1L

In G13, you still use that formula to some extent to solve the molarity of NH4NO3, although the calculation is not shown in the solution manual. The equation M1V1=M2V2 becomes (0.20 M) (1.0 L) = (x) (1.0 + 3.0 L) which leads to the knowledge that the molarity of the diluted solution is 0.050 M. You ...

Nicholas Carpo 1L

I am a confused by whether significant figures in solutions should be limited by the number of significant figures in constants. For example: If my given frequency is 5.11111 x 10^14 Hz (6 Significant Figures) and the constant for speed of light I use is 3.00 x 10^8 m/s (3 Significant Figures), shou...

Nicholas Carpo 1L

If you are talking about question G5 in the textbook, these are the steps you would need to take. First solve for the molar mass of Na2CO3. Na2CO3= (22.99x2)+12.01+(16.00x3) = 105.99g/mol Solve for the molarity of Na2CO3. M = 2.111g / [(105.99g/mol)(0.2500 L) = 0.07967 M You would then need to incor...

Nicholas Carpo 1L

You can assume a 100g sample since the percentages add up to 100g to first find the empirical formula. C:74.03g/12.01g/mol = 6.164mol H:8.70g/1.01g/mol = 8.614mol N:17.27g/14.01g/mol = 1.233mol Simplify the ratios by dividing by the smallest result and rounding up. C:6.164/1.233 = 5 H:8.614/1.233 = ...

Nicholas Carpo 1L

I think for the sake of uniformity, it would be better to use M for molarity because there are several ways concentration can be denoted (ie. molality). It's just for the sake of having a specific unit. Also, since we would be using the carbon element a lot which is also denoted by C, it might becom...

CHEMISTRY COMMUNITY

Search found 36 matches

Re: Hydrogen bonding

Re: strong acid

Re: strong vs weak acids

7th ed 6A.9 c

Re: lone pairs

Re: Trend of Electronegativity

Re: polarizing power and polarizability

Coordination Compounds and Ligands

E- Promotion vs Hybridization

Re: 7th Edition 2F.15

Re: Determining Location of Lone Pair

Re: Seesaw shape

Re: Lone Pairs of Electrons

Re: Drawings of Molecular Shape

H-Bonding

Re: Dipole moment

Re: VSEPR determining shape

Re: Acid vs base [ENDORSED]

Re: Cation and Anion Size

Re: Energy of an Electron

Highly Distorted Electrons?

Re: Principal Quantum Number - Periodic Table

Re: Valence Electrons

Re: Quantum spin number and wave function

Re: Calculating Uncertainty in Momentum

Corresponding Wavelength/Frequency for Each Type of Wave?

Re: Problem 1.3, Seventh edition

Significant Figures for Adding Numbers in Scientific Notation

Re: Problem 1A.15

Re: Question 1B.7 7th Edition

Re: Intensity

Re: Formula M1V1=M2V2 [ENDORSED]

Should Significant Figures be affected by constants?

Re: Volume of Solution

Re: Question 7 on Module 1 Post-Assessment [ENDORSED]

Re: Would it be acceptable to use the term concentration (C) for molarity (M) of a solution?