CHEMISTRY COMMUNITY

Jaedyn_Birchmier3F

Strong bases usually have a cation from groups one or two and then either an oxide or hydroxide at the end.

Jaedyn_Birchmier3F

I am slightly confused on how to know if a salt will make a solution more acidic or basic. I know that highly charged cations such as Fe3+ makes the solution more acidic but why does this happen?

Jaedyn_Birchmier3F

You can find Ka and Kb by using the same reaction. Ka just means the concentration of products/reactants of an acidic reaction and Kb means the concentration of products/reactants of a basic reaction.

Jaedyn_Birchmier3F

Do the shapes coincide with the VSPER shapes or are they different. For example is a coordination compound with 3 bonds and one set of lone pairs a tetrahedral shape or a trigonal pyramidal shape?

Jaedyn_Birchmier3F

Water is known as an amphoteric compound as it has both acidic and basic character. Depending on the situation it can act as an acid or a base.

Jaedyn_Birchmier3F

To add onto this, Arrhenis acids and bases are defined as the acids is the compound that contains hydrogen and reacts with water to from hydrogen ions. On the other hand Arrhenis bases are the compounds that produce hydroxide ions in H2O.

Jaedyn_Birchmier3F

Isoelectric means that two atoms have the same number of valence electrons. F- would have 8 valence electrons. O- would have 7 valence electrons. N2- would have 7 valence electrons. Therefore these two atoms are not isoelectronic to F- as they both have one less valence electron.

Jaedyn_Birchmier3F

In lecture, professor Lavelle was talking about how pi bonds are different than sigma bonds because they do not rotate a certain way so the positions of the atoms are locked. What does this do in particular to specific molecular shapes?

Jaedyn_Birchmier3F

I was just wondering if the only topics on test 3 are going to be VSEPR and hybridization. These seem to be the only two concepts covered in the Lavelle's lectures.

Jaedyn_Birchmier3F

The safest way is to memorized the different bond angles associated with each kind of shape and then know what would happen if there are lone pairs as lone pairs make the angles smaller due to higher repulsion.

Jaedyn_Birchmier3F

Im pretty sure on the test we are supposed to draw out the 2D lewis structure with the dotted line or filled in triangle to represent the 3D shape. We also need to draw the lone pair in the correct place so the shape of the molecule is correct.

Jaedyn_Birchmier3F

Regions of high electron density and high electron concentration relate to the same thing. Both are spaces where many electrons are found.

Jaedyn_Birchmier3F

A rod shape has a higher boiling point than a spherical shape because the shape has an effect on how much attraction an atom feels to another atom. Rod shape would have a higher boiling point because the attractive forces are closer, therefore the bond is stronger and needs more heat to break.

Jaedyn_Birchmier3F

Dipole- Dipole interactions are weaker than hydrogen bonding because dipoles don't create a bond at all, it is more of a moment. Dipole- Dipole interactions are based on something called Van Der Waals forces which are much weaker than hydrogen bonds. These forces occur when there is a moment in whic...

Jaedyn_Birchmier3F

Bond angles are determined by the shape of the molecule. For example BF3 is a trigonal planar shape so therefore all of the B-F angles are 120 degrees.

Jaedyn_Birchmier3F

For the midterm should we assume the atom with the lowest ionization energy is the central atom unless otherwise stated?

Jaedyn_Birchmier3F

Not all Lewis structures need to have a formal charge of 0, it depends on the molecule. For example ammonium has a formal charge of +1 because the molecule itself is NH4+. Therefore, don't always a assume a formal charge of 0 is necessary.

Jaedyn_Birchmier3F

To add onto this, Lewis structures are very very simple drawings of an atom. Therefore, an atom is an average of all the different resonance structures as we can never have an exact idea where an electron is in an atom. Albert is correct when he states that experimentally bond lengths are the same i...

Jaedyn_Birchmier3F

Since there are no longer modules, I would recommend watching a video of the specific topic or going over lecture notes and then do all the homework problems assigned. Since it is guaranteed there will be a problem from the homework on the test, it would be beneficial to go through all problems and ...

Jaedyn_Birchmier3F

No, constants do not need to be memorized. The equation sheet with the constants given during the test can be found on Dr. Lavelle's class website.

Jaedyn_Birchmier3F

One of the problems on the last test for the quantum world was talking about how a battery made of Neon only releases electrons at certain voltages and from this what can we tell about the energy levels of Neon. I wasn't really sure how to answer this because I know about work energy and how it rela...

Jaedyn_Birchmier3F

The Heisenberg Uncertainty equation is used to predict either the possible position or velocity of an electron in an atom. Velocity is a wavelike property of an electron and position is a particle like property of the electron because according to Einsteins principle an electron has both particle an...

Jaedyn_Birchmier3F

Since we are dealing with the energy levels n=4 and n=2 you have to plug the n values into the equation and as you stated the equation has an n squared on the bottom. N= 4 squared would be 16 and n=2 squared would be 4. This is how those numbers in the denominater came about.

Jaedyn_Birchmier3F

Everything with a mass has wavelength properties, but mass has an affect on if the wavelength properties (wavelength) are able to be measure. De Brogile's equation gives this as it is wavelength = h/p. P is mass time velocity therefore if the mass is larger it will make the wavelength much smaller a...

Jaedyn_Birchmier3F

In lecture on Monday Dr. Lavelle talked about the experiment pertaining to the photoelectic effect. The amount of energy needed to remove an electron from a metal relies solely on the amount fo photons present and in this case amplitude is not relevant as it is a wave property.

Jaedyn_Birchmier3F

Shells are otherwise known as energy levels which are what the letter n represents. For example hydrogen only has one electron. Meaning it can only have one shell which would be considered the first energy level or n=1. On the other hand, an atom of an element with more electrons like sodium which h...

Jaedyn_Birchmier3F

I'm a little confused on how the units cancel out for the equation E= hv. Planck's constant is represented in J x s while frequency is represented in Hertz. How does the multiplication of Hertz with Joules and seconds end up canceling out to just have E in units of Joules?

Jaedyn_Birchmier3F

This question was just asked by someone today in class. Professor Lavelle stated that the answer can be given in either liter or mililiters unless it is specifically specified to give it in a certain unit.

Jaedyn_Birchmier3F

when finding the percent yield, is the actual yield always given to you? Since percent yield= actual yield/theoretical yield, I would have to assume that you are always given the actual yield because you are only able to calculate the theoretical yield as the actual yield is almost always different...

Jaedyn_Birchmier3F

When using significant figures, do you use significant figures throughout your whole calculation (for example if the given significant figures is 2, but I am using molar mass and the molar mass contains 4 significant figures then do I change the molar mass to 2 significant figures or leave as is) o...

CHEMISTRY COMMUNITY

Search found 30 matches

Re: Bases

Neutralization

Re: Strength of bases

Re: How to determine shape of coordination compound

Re: Water

Re: Bronsted v. Lewis v. Arrhenius

Re: Isoelectronic

Hybridization and molecular shape

Test 3

Re: bond angle

Re: Drawing Molecules

Re: electron density/concentration

Re: Boiling point

Re: Dipole - Dipole vs. Hydrogen Bonding

Re: Bond Angles

Midterm Question about Central Atom in Lewis Structure

Re: Formal Charge and the Octet Rule

Re: Double Bonds and Single Bonds in Resonance Structures

Re: Replacement for Modules

Re: Numbers to memorize [ENDORSED]

Conceptual Test question

Re: What the equation is used for

Re: Calculating Electron Transmission for H-atom

Re: does everything have a wavelength

Re: ejecting electrons

Re: Shells?

Units

Re: Units - L or mL? [ENDORSED]

Re: Percent yield

Re: Significant Figures