Search found 50 matches

by Natalie Nartz 4F
Mon Dec 02, 2019 9:30 pm
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Ionization in Water
Replies: 8
Views: 303

Re: Ionization in Water

When in contact with water, strong acids and bases are able to fully dissociate due to their high Ka and Kb values. However weak acids and weak bases have lower Ka and Kb values so they are not able to completely ionize in water.
by Natalie Nartz 4F
Mon Dec 02, 2019 9:27 pm
Forum: Polyprotic Acids & Bases
Topic: Defintion
Replies: 11
Views: 381

Re: Defintion

You know an acid is polyprotic when the acid can donate more than one proton to the solution. Examples would include H2S, H2CO3, H2SO4, etc
by Natalie Nartz 4F
Mon Dec 02, 2019 9:24 pm
Forum: Lewis Acids & Bases
Topic: Acidic or Basic
Replies: 3
Views: 39

Re: Acidic or Basic

Examples of basic items would be bleach, baking soda, soapy water, and ammonia solution. Examples of acidic items would be lemon juices, gastric acid, and black coffee. Pure, distilled water is neutral
by Natalie Nartz 4F
Mon Dec 02, 2019 9:20 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Stronger Acid than another
Replies: 5
Views: 34

Re: Stronger Acid than another

A lower pKa indicates a stronger acid. A low pKa means the Ka value is higher, meaning the acid dissociates faster, therefore making it stronger
by Natalie Nartz 4F
Mon Dec 02, 2019 9:18 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pOH
Replies: 6
Views: 53

Re: pOH

To calculate pOH you could take the -log[OH-] or you could subtract the pH from 14. ( 14 = pH + pOH ) Either way the calculation of pOH is nothing to worry about :)
by Natalie Nartz 4F
Wed Nov 27, 2019 5:41 pm
Forum: Hybridization
Topic: Sigma and Pi Bonds
Replies: 21
Views: 96

Re: Sigma and Pi Bonds

Every bond has a sigma bond. A single bond has one sigma bond. A double bond has one sigma bond and one pi bond. A triple bond has one sigma bond and two pi bonds.
by Natalie Nartz 4F
Wed Nov 27, 2019 5:39 pm
Forum: Lewis Acids & Bases
Topic: HCl vs HF
Replies: 19
Views: 118

Re: HCl vs HF

HCl is a stronger acid than HF. Since the fluorine atom is more electronegative the attraction between H and F will be greater than H and Cl, meaning that HCl will dissociate more likely than HF, making it a stronger acid
by Natalie Nartz 4F
Wed Nov 27, 2019 5:36 pm
Forum: Bond Lengths & Energies
Topic: Bond Length
Replies: 10
Views: 97

Re: Bond Length

We don't actually have to calculate bond length quantitatively. Just remember single bonds are longer than double and triple bonds
by Natalie Nartz 4F
Wed Nov 27, 2019 5:34 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Cis vs Trans
Replies: 21
Views: 230

Re: Cis vs Trans

The main distinction is that the cis- isomer is polar and the trans- is nonpolar
by Natalie Nartz 4F
Wed Nov 27, 2019 5:33 pm
Forum: Lewis Acids & Bases
Topic: Proton acceptor and proton donor?
Replies: 33
Views: 186

Re: Proton acceptor and proton donor?

According to the Bronsted-Lowry defintion, acids are proton donors and bases are proton acceptors
by Natalie Nartz 4F
Tue Nov 19, 2019 5:16 pm
Forum: Lewis Structures
Topic: double and triple bonds
Replies: 6
Views: 80

Re: double and triple bonds

Make sure that your formal charges equal the charge of the molecule, however they should still be minimized. Electrons should be counted before drawing the molecule to help determine how many bonds/lone pairs you will have
by Natalie Nartz 4F
Tue Nov 19, 2019 5:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Predicting ditortion
Replies: 2
Views: 21

Re: Predicting ditortion

The VSEPR helps you qualitatively estimate bond angles based on the properties of the molecule, however it can not quantitatively give the exact bond angles
by Natalie Nartz 4F
Tue Nov 19, 2019 5:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone-bonding pair repulsion
Replies: 2
Views: 20

Re: Lone-bonding pair repulsion

Lone pairs are more repulsive because they are less stable, bonding pairs are more stable because they are distributed between two atoms and therefore have a lower repulsion than lone pair.
by Natalie Nartz 4F
Tue Nov 19, 2019 5:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Intermolecular Forces
Replies: 2
Views: 33

Re: Intermolecular Forces

It would be beneficial to know: ion-dipole, h-bond, dipole-dipole, ion-induced dipole, dipole-induced dipole, and dispersion
by Natalie Nartz 4F
Wed Nov 13, 2019 10:11 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Similar terms
Replies: 3
Views: 32

Re: Similar terms

London dispersion forces are temporary attractive forces the results when two electrons in two adjacent atoms occupy positions that create temporary dipoles. This why london dispersion forces can also be called induced dipole-induced dipole attraction.
by Natalie Nartz 4F
Wed Nov 13, 2019 10:08 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: ion-dipole
Replies: 2
Views: 23

Re: ion-dipole

An ion-dipole force occurs between an ion and a dipole. When a polar molecule and an ion come together, the cation will be attracted to the partially negative end of the polar molecule, and the anion will be attracted to the partially positive end. For example an ion dipole force can be generated be...
by Natalie Nartz 4F
Wed Nov 13, 2019 10:04 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Covalent bonding
Replies: 5
Views: 38

Re: Covalent bonding

A covalent bond would be classified as a intramolecular force as it occurs within a molecule. Covalent bonds are intramolecular because they hold atoms together in molecules and polyatomic ions.
by Natalie Nartz 4F
Wed Nov 13, 2019 10:01 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Molecule Size and Melting Points
Replies: 6
Views: 43

Re: Molecule Size and Melting Points

This is true, as molecules increase in size, their boiling point increases. This is because large molecules have more electrons and nuclei which creates stronger intramolecular forces like van der waals which then increases the boiling point.
by Natalie Nartz 4F
Wed Nov 13, 2019 9:59 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Intermolecular Forces vs. Chemical Bonds
Replies: 3
Views: 22

Re: Intermolecular Forces vs. Chemical Bonds

A chemical bond is an attractive force between two atoms, sharing or exchange of electrons. Intermolecular forces are forces that occur between two or more molecules, and are much weaker than bonds.
by Natalie Nartz 4F
Mon Nov 04, 2019 6:22 pm
Forum: Lewis Structures
Topic: How do I know when to use a double bond?
Replies: 7
Views: 68

Re: How do I know when to use a double bond?

Depends on the situation, just pay attention to the number of electrons and the octet rule
by Natalie Nartz 4F
Mon Nov 04, 2019 6:19 pm
Forum: Dipole Moments
Topic: Interactions between Ions and Molecules
Replies: 5
Views: 47

Re: Interactions between Ions and Molecules

If magnitude is greater, the bond is harder to break, because it has the most potential energy stored in its bonds.
by Natalie Nartz 4F
Mon Nov 04, 2019 6:09 pm
Forum: *Shrodinger Equation
Topic: Shrodinger equation
Replies: 7
Views: 104

Re: Shrodinger equation

I don't believe we'll need to memorize this for the exam. I think Lavelle even mentioned an alternative equation to use instead.
by Natalie Nartz 4F
Mon Nov 04, 2019 6:07 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Atomic Orbitals
Replies: 4
Views: 64

Re: Atomic Orbitals

I am not 100% sure, but I believe it is referring to the probability function that corresponds to every electron. The function tells us the probability of finding an electron within that orbital. I hope this helps!
by Natalie Nartz 4F
Mon Nov 04, 2019 6:04 pm
Forum: Ionic & Covalent Bonds
Topic: Names and chemical formulas
Replies: 5
Views: 37

Re: Names and chemical formulas

I it couldn't hurt to memorize common polyatomic ions like ammonium and carbonate, etc, but I wouldn't stress about it.
by Natalie Nartz 4F
Wed Oct 30, 2019 1:41 am
Forum: Lewis Structures
Topic: Drawing lewis structures
Replies: 8
Views: 67

Re: Drawing lewis structures

I am not sure if we will be covering bond angles in class, but if we don't I think you're fine as long as correctly distribute the electrons.
by Natalie Nartz 4F
Wed Oct 30, 2019 1:38 am
Forum: Administrative Questions and Class Announcements
Topic: posting on chemistry community
Replies: 11
Views: 167

Re: posting on chemistry community

Homework problems from the textbook are due in during your discussion time. Posts on chemistry community are due 11:59 pm Sunday night.
by Natalie Nartz 4F
Wed Oct 30, 2019 1:33 am
Forum: Trends in The Periodic Table
Topic: 1F.5a
Replies: 4
Views: 29

Re: 1F.5a

The periodic trends show that ionization energy increases when moving left to right. This is because when moving left to right across a period, atomic radius decreases, so electrons are more attracted to the nucleus. With this in mind, since Na is further left, it will have a lower ionization energy...
by Natalie Nartz 4F
Wed Oct 30, 2019 1:26 am
Forum: Lewis Structures
Topic: Resonance
Replies: 4
Views: 33

Re: Resonance

Resonance is way of describing bonding certain molecules in a combination of different ways. The chemical connectivity is the same however, the distribution of electrons varies in each structure. And it is the average of these structures, that we get the true structure of the molecule.
by Natalie Nartz 4F
Wed Oct 30, 2019 1:21 am
Forum: Properties of Light
Topic: Midterm Exam
Replies: 21
Views: 218

Re: Midterm Exam

How many questions will the midterm be? What type? (multiple choice/open ended)
by Natalie Nartz 4F
Tue Oct 22, 2019 1:01 am
Forum: Trends in The Periodic Table
Topic: 2nd Ionization Energy
Replies: 7
Views: 50

Re: 2nd Ionization Energy

When removing an electron in the first ionization you ultimately make the atom more positive, which makes it harder for the second removal of an electron since now there is a stronger positive charge pulling on the electron.
by Natalie Nartz 4F
Tue Oct 22, 2019 12:58 am
Forum: Trends in The Periodic Table
Topic: Radii Trends
Replies: 3
Views: 28

Re: Radii Trends

Yes atomic, ionic, and covalent radii all share the same trend. Radius decreases across a period, and increases down a group
by Natalie Nartz 4F
Tue Oct 22, 2019 12:54 am
Forum: Quantum Numbers and The H-Atom
Topic: 1D. 23)
Replies: 5
Views: 72

Re: 1D. 23)

For part A, n= 2 and l=1 which makes it 2p, the p-subshell has three orbitals: 2px, 2py, 2pz. For part B n=4 l=2 and ml= -2 which represents only one orbital

I hope this help
by Natalie Nartz 4F
Tue Oct 22, 2019 12:45 am
Forum: Ionic & Covalent Bonds
Topic: Week 4 Homework
Replies: 9
Views: 117

Re: Week 4 Homework

I believe we are still on the quantum world unit, so I would just do problems from this section.
by Natalie Nartz 4F
Tue Oct 22, 2019 12:43 am
Forum: Quantum Numbers and The H-Atom
Topic: Orbital Angular Momentum
Replies: 3
Views: 29

Re: Orbital Angular Momentum

l is the angular momentum quantum number. Each value of l corresponds to a specific subshell and shape. Ex: l=0 would be the s subshell which has a spherical shape

I hope this helped
by Natalie Nartz 4F
Tue Oct 15, 2019 3:04 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: EM radiation
Replies: 3
Views: 88

Re: EM radiation

I don't think we'll have to memorize the specific values. But I think memorizing the order of the types of radiation in terms of wavelength would be beneficial. I think it would also be good to memorize the range of visible light which is around 400-700nm
by Natalie Nartz 4F
Tue Oct 15, 2019 3:01 pm
Forum: Properties of Light
Topic: 1.A.3
Replies: 2
Views: 35

Re: 1.A.3

Frequency measures the number of wave cycles in one second. Amplitude on the other hand, is the measured distance between the crest and the midline of a wave. They are independent.
by Natalie Nartz 4F
Tue Oct 15, 2019 2:55 pm
Forum: Einstein Equation
Topic: Meaning of h [ENDORSED]
Replies: 5
Views: 71

Re: Meaning of h [ENDORSED]

h symbolizes planck's constant. It is used in this sense to relate energy in one quantum or photon of electromagnetic radiation to its corresponding frequency.
by Natalie Nartz 4F
Tue Oct 15, 2019 2:50 pm
Forum: Properties of Electrons
Topic: Using masses of protons, neutrons, and electrons
Replies: 7
Views: 98

Re: Using masses of protons, neutrons, and electrons

I don't think we'll have to memorize them. But, the masses of each are as follows

electron: 9.11*10^-31 kg
proton: 1.675*10^-27 kg
neutron: 1.673*10^-27 kg
by Natalie Nartz 4F
Tue Oct 15, 2019 2:45 pm
Forum: DeBroglie Equation
Topic: Textbook Question 1B21
Replies: 3
Views: 47

Re: Textbook Question 1B21

I am not sure where your error is. For my mass I got .146 kg and my velocity was 41.126ms-1 , and I got 1.11*10^-34 as my final answer
by Natalie Nartz 4F
Mon Oct 07, 2019 11:08 pm
Forum: Molarity, Solutions, Dilutions
Topic: Polyatomic ions on Test 1
Replies: 4
Views: 85

Re: Polyatomic ions on Test 1

I am not sure you need to know the structure of the polyatomic ions, but I believe it would be beneficial to memorize common polyatomic ions nitrate, nitrate, sulfate, phophate, etc.
by Natalie Nartz 4F
Mon Oct 07, 2019 11:05 pm
Forum: Limiting Reactant Calculations
Topic: M.9 hw prob
Replies: 4
Views: 69

Re: M.9 hw prob

The net ionic equation would look like this:

Cu+2 + 2OH- = Cu(OH)2

I hope this helps
by Natalie Nartz 4F
Mon Oct 07, 2019 10:57 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Mass Percent
Replies: 2
Views: 35

Re: Mass Percent

First, you need the molar mass of Sr(NO2)2 which is 179.631 g/mol. Then calculate the mass of each element in the molecule, (Sr 87.62g, N 2(14.01g), O 4(16g)) Finally, take each of the element's masses and divide by the molar mass of strontium nitrate, then multiply by 100 to get the mass percent. S...
by Natalie Nartz 4F
Mon Oct 07, 2019 10:46 pm
Forum: Balancing Chemical Reactions
Topic: How to write reactions for tests
Replies: 5
Views: 106

How to write reactions for tests

When writing or balancing equations for tests will we be required to include the state of each element? Ex: solid, liquid, gas, aqueous
by Natalie Nartz 4F
Mon Oct 07, 2019 5:54 pm
Forum: Photoelectric Effect
Topic: How much energy to remove one electron?
Replies: 8
Views: 142

How much energy to remove one electron?

I am not sure how to determine the energy needed to remove one electron from a sodium atom.
The given information is as follows:
- velocity of the ejected electron is 6.61 x 105 m.s-1
- work function for sodium is 150.6 kJ.mol-1
What equation would be best in this situation?
by Natalie Nartz 4F
Tue Oct 01, 2019 11:22 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Equation Question
Replies: 2
Views: 71

Equation Question

Why is the equation En= -(hR)/(n^2) negative? Does this deal with certain properties of the atom and/or electron?
by Natalie Nartz 4F
Tue Oct 01, 2019 11:19 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Photon Absorption/Emission
Replies: 8
Views: 125

Photon Absorption/Emission

Does absorption of a photon always lead to a later emission of a photon? If so, does this emitted photon have the same energy as the photon that was first absorbed?
by Natalie Nartz 4F
Tue Oct 01, 2019 11:17 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Frequency doesn't match energy difference
Replies: 2
Views: 83

Frequency doesn't match energy difference

When frequencies of light don’t match the energy differences of an atom, what happens to the light? Does this light simply pass through?
by Natalie Nartz 4F
Tue Oct 01, 2019 11:09 am
Forum: Empirical & Molecular Formulas
Topic: Rounding [ENDORSED]
Replies: 12
Views: 147

Re: Rounding [ENDORSED]

Refrain from rounding values within the problem it self when you are doing calculations. From my understanding, it is only appropriate to round to the correct number of significant figures when you have reached your final answer.
by Natalie Nartz 4F
Tue Oct 01, 2019 11:06 am
Forum: SI Units, Unit Conversions
Topic: Significant 0’s [ENDORSED]
Replies: 8
Views: 415

Re: Significant 0’s [ENDORSED]

0.0850 would have 3 sig figs, as the two zeros before the 8 are not significant. However the trailing zero following the 5 would be significant

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