CHEMISTRY COMMUNITY

Kaitlynn Tran 3F

Matt Sanruk 4F wrote:Is cisplatin a chelating ligand or is it a complex compound?

Cisplatin isn't a chelating ligand because there are no polydentate ligands in it

Kaitlynn Tran 3F

Leila_4E wrote:In organic molecules where they don't show the carbon atoms or lone pairs, do we assume that there are lone pairs around Oxygens or hydrogens...?

You would assume that each atom has however many lone pairs it would need for a complete octet

Kaitlynn Tran 3F

Nikki Razal 4E wrote:for question 40c, how do you know whether o2 or o3 has the stronger bond and why?

O₃ is polar because the dipoles do not cancel out, so there are dipole-dipole intermolecular forces. The resonance due to the double bond also would cause it to have a stronger bond than O₂.

Kaitlynn Tran 3F

First, remember to say the strengths of the intermolecular forces between compounds, because it is not the actual intramolecular bonds. Also, NH3 has the greater boiling point, because it actually has hydrogen bonding (remember that you can form hydrogen bonds only on Hydrogens that are bonded to N...

Kaitlynn Tran 3F

So I know that the relative strengths for bonds are ionic > hydrogen > dipole-dipole > london dispersion, and as the bonds get stronger, the boiling point gets higher due to more energy required to break the bond. However, factors such as molecular size and surface area are factors that increase boi...

Kaitlynn Tran 3F

Calculating formal charge is useful when trying to draw the most stable structure as possible. The negative formal charge should go on the most electronegative atom.

Kaitlynn Tran 3F

It doesn't matter which order you calculate formal charge in because each atom's formal charge should be counted individually. You don't need to add up the formal charges at the end, but you can compare each atom's formal charge to ensure that you have the most stable possible structure (i.e. as man...

Kaitlynn Tran 3F

I count each Lewis dot and line around the atom to calculate formal charge. For example, on an oxygen atom that is double bonded to something, there would be 2 lines and 4 valence electrons, resulting in a formal charge of 6.

Kaitlynn Tran 3F

Completing octets is typically prioritized over formal charges when drawing Lewis structures.

Kaitlynn Tran 3F

How do you find/calculate the oxidation number of an atom? Is there an equation or process?

Kaitlynn Tran 3F

Is there a limit to how many valence electrons you can add to an atom that has an expanded octet?

Kaitlynn Tran 3F

Most atoms after P on the periodic table in the d-block can have an expanded octet.

Kaitlynn Tran 3F

Atoms that can have an expanded octet start with P on the periodic table and continue onwards. Aluminum is before P, so it can't have an expanded octet.

Kaitlynn Tran 3F

Atoms in row 3 and below on the periodic table can typically have expanded octets.

Kaitlynn Tran 3F

Electronegative atoms pull more electrons toward them, so the single electron would go on the most electronegative atom. Atoms are generally more electronegative as you move up and toward the right of the periodic table.

Kaitlynn Tran 3F

Oxygen is able to form single, double, or triple bonds depending on the formal charges of an overall structure or the number of electrons needed. Oxygen typically forms double bonds because it allows for a formal charge of 6 with 4 valence electrons.

Kaitlynn Tran 3F

If we are given a molecule with multiple carbons, the structure will not always be in the form of a ring. For example, C4H10 forms a hydrocarbon chain with all the carbon atoms in the center covalently bonded to each other and the hydrogens at the terminal ends. There is no direct central atom beca...

Kaitlynn Tran 3F

OH- has a hydrogen bond, which is stronger than the bond of HS-

Kaitlynn Tran 3F

Elements in period 3 and below on the periodic table can generally have expanded octets.

Kaitlynn Tran 3F

As long as you say either name and know that the bond angle is less than 120, you should be fine!

Kaitlynn Tran 3F

AnayaArnold_3L wrote:Do lone pairs automatically make a molecule nonpolar?

Yes, lone pairs disrupt symmetry, which makes molecules polar.

Kaitlynn Tran 3F

You would have to consider the total number of electrons, formal charges, the octet rule, and exceptions to the octet rule to know when to add a lone pair.

Kaitlynn Tran 3F

Ozone would have 18 electrons, so having 2 double bonds (and no lone pairs on the central atom due to the octet rule) would only have 16 electrons.

Kaitlynn Tran 3F

Sulfur is the only central atom in H₂SO₅, so there are no cis/trans isomers

Kaitlynn Tran 3F

Figure out what variables are given and what variable they are asking you to find. Then choose whichever formula that uses the information given in order to find the unknown variable.

Kaitlynn Tran 3F

You can review midterm problems and homework questions from Chapter 1.

Kaitlynn Tran 3F

Light constantly acts like both a wave and a particle.

Kaitlynn Tran 3F

Calculations are more common, but there will probably be 2 or 3 conceptual questions. However, most times you have to know concepts in order to know how to calculate.

Kaitlynn Tran 3F

Your answer should have the same number of sig figs as the number with the least amount of significant figures given in the problem.

Kaitlynn Tran 3F

Only the first number after the 0's would count as the first significant figure.

Kaitlynn Tran 3F

Double bonds affect bond strength, but it doesn't affect melting point.

Kaitlynn Tran 3F

As atoms get larger, they become less electronegative because the electron cloud gets farther away from the nucleus.

Kaitlynn Tran 3F

It is anywhere that has potential to form a hydrogen bond. Essentially, it is any lone pair on an N, O, or F atom.

Kaitlynn Tran 3F

I tend to think of hybridization in terms of areas of electron density. So you can figure out hybridization by counting the number of sigma bonds and lone pairs.

Kaitlynn Tran 3F

Victor James 4I wrote:so the s-character is a ratio of s orbitals to the other hybridized orbitals?

Yes, it's typically written as a percentage!

Kaitlynn Tran 3F

It can have 1 or 2 lone pairs. If you look at the shape of a trigonal planar molecule, it looks like the shape of a bent molecule. The difference is that instead of 3 atoms around the central atom, there are 2 atoms and a lone pair around the central atom, making it have a bent shape. The same conce...

Kaitlynn Tran 3F

If it has 0, 3, or 4 lone pairs, the molecular shape will be linear. However, if it has 1 or 2 lone pairs, the molecular shape will be bent.

Kaitlynn Tran 3F

Micah3J wrote:Is there a difference between bent and angular? Or is it just another way of saying the same thing?

These are interchangeable terms for the same shape! They both describe the molecular shape that has a bond angle of <120 degrees.

Kaitlynn Tran 3F

Bent molecules can have the VSEPR formula AX₂E or AX₂E₂. Linear molecules can have the VSEPR formula AX₂, AX₂E, or AX₂E₃. It depends on the number of lone pairs and how the regions of electron density affect the shape of the molecule.

Kaitlynn Tran 3F

The VSEPR formula is a way to denote how many central atoms, bonded atoms, and lone-pairs there are on the molecule. It follows the pattern of A n X n E n , where A is the central atom, X is a bonded atom, E is a lone pair, and the subscript n is the number of each. So a molecule with 3 bonded atoms...

Kaitlynn Tran 3F

T-shaped molecules have bond angles of 90 degrees. A molecule is T-shaped if there are 3 molecules around the central atom and 2 lone pairs, or if there are 3 molecules around the central atom and 3 lone pairs.

Kaitlynn Tran 3F

Most of the common hybridization combinations have n=2 as the coefficient

Kaitlynn Tran 3F

Is there a way to tell if a molecule is hybridized just by looking at it?

Kaitlynn Tran 3F

Why is there a triple bond for CO instead of a double bond?

Kaitlynn Tran 3F

How do you determine if a molecule exhibits delocalized bonding?

Kaitlynn Tran 3F

Hydrogen bonds only occur when hydrogen is bonded to N, O, or F, right?

Kaitlynn Tran 3F

When do dipole-dipole moments cancel out for tetrahedral molecules?

Kaitlynn Tran 3F

When drawing structures, how do I know when to add a double bond instead of a lone pair around an atom? For example, in H2CO, how do I know to add a double bond between C=O instead of giving O 3 lone pairs?

Kaitlynn Tran 3F

What is the difference between a subshell and an orbital? Are they the same thing?

Kaitlynn Tran 3F

If you are given a percentage in a problem, it is easy to imagine that you have a total of 100g. So theoretically, if you have 16% C, you can assume there are 16g C. With the amount in grams, you can convert to moles to find the ratio for empirical formula.

Kaitlynn Tran 3F

It is common for actual yield to be less than theoretical yield due to human error or device error. Substances can stick to containers, things can be measured incorrectly, etc.

Kaitlynn Tran 3F

Showing all your work will help your chances of getting more points because they grade based on your method and calculations. Even if your final answer is wrong, you can still get partial credit for any work that you did correctly.

Kaitlynn Tran 3F

Multiply by 10^n to get to a smaller unit, and divide by 10^n to get to a smaller unit. In simpler terms, you can move the decimal to the right for smaller units or to the left for larger units.

Kaitlynn Tran 3F

After using Avogadro's number for conversion, your answer will be in atoms, molecules, or formula units depending on the context of the question.

Search found 54 matches