Search found 50 matches

by Jacob Villar 3K
Mon Dec 02, 2019 12:01 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Explain VSEPR conceptually
Replies: 12
Views: 37

Re: Explain VSEPR conceptually

VSEPR is a model that shows atomic structure, but with the inclusion of factors such as bond angles and electron repulsion.
by Jacob Villar 3K
Sun Dec 01, 2019 10:55 pm
Forum: Bronsted Acids & Bases
Topic: How to determine if a molecule is a bronsted acid or base?
Replies: 3
Views: 13

Re: How to determine if a molecule is a bronsted acid or base?

A bronsted acid donates protons, whereas a bronsted base accepts protons.
by Jacob Villar 3K
Sun Dec 01, 2019 10:53 pm
Forum: Lewis Acids & Bases
Topic: Weak vs. Strong
Replies: 8
Views: 30

Re: Weak vs. Strong

Stronger acids/bases are completely ionized (dissociated) in solution or water respectively.
by Jacob Villar 3K
Sun Dec 01, 2019 10:51 pm
Forum: Sigma & Pi Bonds
Topic: Sigma vs. Pi
Replies: 13
Views: 30

Re: Sigma vs. Pi

Sigma bonds are stronger due to the orbital overlap.
by Jacob Villar 3K
Sun Dec 01, 2019 9:33 pm
Forum: Lewis Acids & Bases
Topic: Strong Acids
Replies: 5
Views: 14

Re: Strong Acids

Long bonds attribute to stronger acids, since they are weaker bonds, and therefore, the acids can be dissociated to a greater degree.
by Jacob Villar 3K
Sun Dec 01, 2019 9:28 pm
Forum: Resonance Structures
Topic: Formal Charge Question
Replies: 15
Views: 68

Re: Formal Charge Question

Yeah the resonance structures should amount to the same overall charge.
by Jacob Villar 3K
Sun Nov 24, 2019 11:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AXE Format
Replies: 34
Views: 96

Re: AXE Format

I think writing simply X or E would be sufficient.
by Jacob Villar 3K
Sun Nov 24, 2019 11:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: t shape and see saw
Replies: 6
Views: 22

Re: t shape and see saw

It depends on bonding pairs vs lone pairs in an atom, as seesaw has 4 bonding pairs, but 1 lone pair, whereas t-shape only has 3 bonding pairs, but 2 lone pairs.
by Jacob Villar 3K
Sun Nov 24, 2019 11:30 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hydrogen Bonding
Replies: 13
Views: 47

Re: Hydrogen Bonding

Yes, since hydrogen bonds form with the elements N, O, and F, and these are more electronegative atoms.
by Jacob Villar 3K
Sun Nov 24, 2019 11:07 pm
Forum: Resonance Structures
Topic: Lone Pairs
Replies: 3
Views: 17

Re: Lone Pairs

They arrange themselves to experience as small amount of repulsion as possible.
by Jacob Villar 3K
Sun Nov 17, 2019 10:21 pm
Forum: Dipole Moments
Topic: Polarity
Replies: 7
Views: 38

Re: Polarity

Since CCl4 is a symmetrical tetrahedral shape, the dipole moments do cancel out.
by Jacob Villar 3K
Sun Nov 17, 2019 10:09 pm
Forum: Dipole Moments
Topic: Cancelling dipole moments
Replies: 7
Views: 51

Re: Cancelling dipole moments

A dipole moment can be considered cancellable if the dipole moments move in opposite directions, and their magnitude is the same.
by Jacob Villar 3K
Sun Nov 17, 2019 9:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 7
Views: 41

Re: Bond Angles

The lone pairs located on a central atom will repel the electrons located within covalent bonds, thus decreasing the bond angles.
by Jacob Villar 3K
Sun Nov 17, 2019 9:46 pm
Forum: Bond Lengths & Energies
Topic: Electron Density
Replies: 10
Views: 28

Re: Electron Density

Yes, and they can play a role in the shape of a molecule in changing the angles between atoms.
by Jacob Villar 3K
Sun Nov 17, 2019 9:45 pm
Forum: Bond Lengths & Energies
Topic: Shorter bond lengths
Replies: 12
Views: 53

Re: Shorter bond lengths

Since there is a greater amount of electrons involved in bonding, the atoms are able to pull closer together, creating a shorter bond length.
by Jacob Villar 3K
Sun Nov 17, 2019 9:41 pm
Forum: Resonance Structures
Topic: Formal Charge Question
Replies: 15
Views: 68

Re: Formal Charge Question

The total formal charge should be equal between resonance structures, although the charges of the individual atoms may differ.
by Jacob Villar 3K
Sun Nov 10, 2019 11:00 pm
Forum: Bond Lengths & Energies
Topic: Dissociation Energy
Replies: 9
Views: 22

Re: Dissociation Energy

Energy is absorbed to be able to break bonds.
by Jacob Villar 3K
Sun Nov 10, 2019 10:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Writing e- Configurations
Replies: 15
Views: 72

Re: Writing e- Configurations

Unless specifically stated to write out the full electron configuration, I believe writing the configuration with the noble gas abbreviation would suffice.
by Jacob Villar 3K
Sun Nov 10, 2019 10:55 pm
Forum: Electronegativity
Topic: Iodine
Replies: 6
Views: 24

Re: Iodine

The London dispersion forces within I2 are much stronger due to its larger atomic radius.
by Jacob Villar 3K
Sun Nov 10, 2019 10:54 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: London Forces
Replies: 3
Views: 10

London Forces

I just want to clarify based on the lecture from Friday, but London forces occur in all molecules/atoms right?
by Jacob Villar 3K
Sun Nov 10, 2019 10:51 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths and strength
Replies: 4
Views: 13

Re: Bond lengths and strength

The extra electrons in the double bonds attract the atoms closer together, thereby reducing the length of the double bonds, yet also increasing its strength.
by Jacob Villar 3K
Sun Nov 10, 2019 10:50 pm
Forum: Formal Charge and Oxidation Numbers
Topic: central atom
Replies: 21
Views: 89

Re: central atom

At a formal charge of zero, the atom would be the most stable, so yes.
by Jacob Villar 3K
Sun Nov 03, 2019 10:14 pm
Forum: Dipole Moments
Topic: Dipole Arrow
Replies: 5
Views: 30

Re: Dipole Arrow

In chemistry, it is pointed towards the negative dipole.
by Jacob Villar 3K
Sun Nov 03, 2019 10:06 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Character
Replies: 3
Views: 17

Covalent Character

Can someone explain to me what exactly covalent character is, what factors affect how great it is, and what the result of a high or low covalent character is?
by Jacob Villar 3K
Sun Nov 03, 2019 10:02 pm
Forum: Bond Lengths & Energies
Topic: Strength of Bonds
Replies: 16
Views: 40

Re: Strength of Bonds

Shorter bonds are generally stronger, and longer bonds tend to be weaker.
by Jacob Villar 3K
Sun Nov 03, 2019 10:01 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Chemical Equations
Replies: 4
Views: 37

Re: Balancing Chemical Equations

I believe that if you put these coefficients (from left to right) it should be balanced: 6, 10, 5, 3, 6, 9.
by Jacob Villar 3K
Sun Nov 03, 2019 9:56 pm
Forum: Sigma & Pi Bonds
Topic: Double bond
Replies: 15
Views: 99

Re: Double bond

Most often double bonds are drawn in order to keep in line with the octet rule.
by Jacob Villar 3K
Sun Oct 27, 2019 11:45 pm
Forum: Lewis Structures
Topic: Lone Pairs
Replies: 12
Views: 40

Re: Lone Pairs

Lone pairs are the dots on a lewis structure that do not form bonds, for example, on an atom, they would be the two dots on the side.
by Jacob Villar 3K
Sun Oct 27, 2019 10:38 pm
Forum: Octet Exceptions
Topic: Exceptions
Replies: 3
Views: 40

Re: Exceptions

H, He, Li, and B are exceptions to the octet rule because their amount of electrons are only enough to reach the 1s orbital, and therefore, the octet rule cannot be applied in these circumstances.
by Jacob Villar 3K
Sun Oct 27, 2019 10:33 pm
Forum: Ionic & Covalent Bonds
Topic: Single bond vs. Double bond vs. Triple bond
Replies: 3
Views: 33

Re: Single bond vs. Double bond vs. Triple bond

I believe that due to the greater amount of attraction between electrons in double bonds and triple bonds, this causes the bond length to be shorter than that of a single bond.
by Jacob Villar 3K
Sun Oct 27, 2019 10:25 pm
Forum: Sigma & Pi Bonds
Topic: Double bond
Replies: 15
Views: 99

Re: Double bond

Sometimes, the octet rule will not be satisfied with simply using single bonds, and therefore double bonds would be necessary to satisfy this rule.
by Jacob Villar 3K
Sun Oct 27, 2019 10:20 pm
Forum: Lewis Structures
Topic: Choosing the central atom
Replies: 16
Views: 52

Re: Choosing the central atom

The atom with the lowest ionization energy is the central atom.
by Jacob Villar 3K
Sun Oct 27, 2019 10:18 pm
Forum: Ionic & Covalent Bonds
Topic: Ionization Energy Unit
Replies: 6
Views: 36

Re: Ionization Energy Unit

kJ/mol, kilojoules per mole
by Jacob Villar 3K
Sun Oct 20, 2019 10:28 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Atomic Orbitals
Replies: 3
Views: 33

Re: Atomic Orbitals

We will learn more about this later, but valence electrons (electrons sitting on the outermost orbital), are important to the bonding between atoms.
by Jacob Villar 3K
Sun Oct 20, 2019 10:16 pm
Forum: Empirical & Molecular Formulas
Topic: Molecular to Empirical Formula
Replies: 10
Views: 79

Re: Molecular to Empirical Formula

You would have to find the molar mass using the empirical formula, and divide the given molar mass by this value. Then with the answer, which is usually a whole number, multiply all the subscripts of the empirical formula by the molar mass ratio.
by Jacob Villar 3K
Sun Oct 20, 2019 10:01 pm
Forum: DeBroglie Equation
Topic: Unit Conversion
Replies: 5
Views: 36

Re: Unit Conversion

Since mega- translates to 10^6, 1 Hz would translate to 1*10^6 mHz
by Jacob Villar 3K
Sun Oct 20, 2019 9:58 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Quantum Number
Replies: 5
Views: 23

Re: Magnetic Quantum Number

The magnetic quantum number labels the different orbitals of a subs [censored].
by Jacob Villar 3K
Sun Oct 20, 2019 9:54 pm
Forum: Properties of Light
Topic: What are the units of hertz
Replies: 41
Views: 211

Re: What are the units of hertz

1 Hz is counted as 1 cycle per second
by Jacob Villar 3K
Sun Oct 13, 2019 11:34 pm
Forum: Significant Figures
Topic: sig figs and periodic tables
Replies: 11
Views: 84

Re: sig figs and periodic tables

Should we bet using sig figs based on given number values (ex: if the problem gives us 250 mL, we use 3 sig figs) or should we be basing the amount of sig figs we use on calculations as we go?
by Jacob Villar 3K
Sun Oct 13, 2019 8:14 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 75
Views: 19017

Re: Final Jitters

I like to let out a big breath before taking the test to help clear my system of anxiety, and often times I'll chew gum because it helps me focus on the material rather than other small things going around in the room, which also saves time for more work on problems.
by Jacob Villar 3K
Sun Oct 13, 2019 8:11 pm
Forum: Balancing Chemical Reactions
Topic: Writing out equations
Replies: 9
Views: 78

Re: Writing out equations

The Hill system shows that the order of listing elements starts with carbon atoms, then hydrogen atoms, and then all other atoms in alphabetical order.
by Jacob Villar 3K
Sun Oct 13, 2019 8:07 pm
Forum: SI Units, Unit Conversions
Topic: knowing how many sig figs to use
Replies: 17
Views: 101

Re: knowing how many sig figs to use

I think that it is proper to use the same amount of sig figs throughout the entire problem, so that there is consistency with each preceding calculation. Especially with given units, the sig figs in your final answer should likely match the amount of sig figs with these given numbers.
by Jacob Villar 3K
Sun Oct 13, 2019 7:57 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Angstrom's Constant
Replies: 5
Views: 46

Angstrom's Constant

So I know that the equivalent of an Angstrom unit is 1A = 10^-10 m, but how would you convert to other significant units such as centimeters or picometers? DO you multiply by tens when converting to smaller units, or do you multiply by tens when converting to larger units
by Jacob Villar 3K
Sun Oct 06, 2019 10:43 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Reactions
Replies: 25
Views: 230

Re: Balancing Reactions

According to the Law of Conservation of Mass, matter cannot be created nor destroyed, and therefore, when balancing a reaction, you must have the same amount of moles on both the reactants and products side in accordance with the conservation of mass.
by Jacob Villar 3K
Thu Oct 03, 2019 8:27 pm
Forum: Balancing Chemical Reactions
Topic: Fractioned Chemical Equations?
Replies: 5
Views: 70

Re: Fractioned Chemical Equations?

Yes, if you were to multiply by 2 to get rid of the fractions it would be correct so long as you multiply the moles of all the reactants and products. Doing so would ensure that the mole ratios remain the same.
by Jacob Villar 3K
Thu Oct 03, 2019 8:19 pm
Forum: Balancing Chemical Reactions
Topic: Understanding how to get whole #s [ENDORSED]
Replies: 18
Views: 139

Re: Understanding how to get whole #s [ENDORSED]

If you're trying to calculate the empirical formula, after finding the moles by converting from grams, divide by the smallest number of moles you received. Afterwards, if you end up with a mole amount of, say 2.5, you would multiply all the moles by an appropriate number to get to a whole number, in...
by Jacob Villar 3K
Thu Oct 03, 2019 8:12 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Actual Yield vs Theoretical Yield
Replies: 6
Views: 44

Re: Actual Yield vs Theoretical Yield

When conducting experiments, there can be a lot of controllable and uncontrollable circumstances that cause yields to differ. Say in a perfect situation, there are no impurities and no errors caused by those conducting the experiment; in this case, the result would represent your theoretical yield, ...
by Jacob Villar 3K
Thu Oct 03, 2019 8:05 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Determining Molar Mass
Replies: 7
Views: 53

Re: Determining Molar Mass

As long as the result isn't too drastically different in terms of significant figures, I would say that using 16 would be fine.
by Jacob Villar 3K
Mon Sep 30, 2019 2:09 am
Forum: Empirical & Molecular Formulas
Topic: Percent Mass Composition
Replies: 7
Views: 118

Percent Mass Composition

Apologies if this question may seem rather simplistic, but in a given problem, why would a given percent mass value, i.e. 49.8% C, also be used in the process of calculating moles? Will the value always be based off of 100 grams?

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