Search found 55 matches

by Parsamokhtar
Mon Dec 02, 2019 10:58 pm
Forum: Bronsted Acids & Bases
Topic: general q
Replies: 2
Views: 18

Re: general q

pH is usually used to refer to a solution. Depending on the ion in solution, the pH varies.
by Parsamokhtar
Mon Dec 02, 2019 10:56 pm
Forum: Polyprotic Acids & Bases
Topic: Polyprotic Question!
Replies: 12
Views: 777

Re: Polyprotic Question!

Polyprotic acids can essentially lose a proton (H+) more than once, or they can lose more than one H+.
by Parsamokhtar
Mon Dec 02, 2019 10:55 pm
Forum: Bronsted Acids & Bases
Topic: Final
Replies: 13
Views: 47

Re: Final

Everything should be in the syllabus. I assume anything else he includes would be mentioned during class.
by Parsamokhtar
Mon Dec 02, 2019 10:54 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pOH
Replies: 6
Views: 22

Re: pOH

I feel like most things will be in terms of pH, but I've seen problems where information is given in pOH which we'd need to use for calculations to maybe determine pH. For that you could use pH + pOH = 14
by Parsamokhtar
Mon Dec 02, 2019 10:52 pm
Forum: Bronsted Acids & Bases
Topic: strong v weak acids
Replies: 8
Views: 27

Re: strong v weak acids

I think you should have a general idea of them. At least the ones he mentioned in class.
by Parsamokhtar
Tue Nov 26, 2019 3:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam
Replies: 5
Views: 43

Re: Final Exam

180/500 so 36%
by Parsamokhtar
Tue Nov 26, 2019 3:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw Shape
Replies: 12
Views: 69

Re: Seesaw Shape

The angle would be less than 90 for axial, and less than 120 equatorial.
by Parsamokhtar
Tue Nov 26, 2019 3:39 pm
Forum: Significant Figures
Topic: Sig Figs on Tests
Replies: 24
Views: 187

Re: Sig Figs on Tests

You should usually give the answer in terms of the number of the value given to you in the problem with the least number of sig figs.
by Parsamokhtar
Tue Nov 26, 2019 3:38 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity Formula / Calculation
Replies: 5
Views: 48

Re: Molarity Formula / Calculation

You would either use
M=moles/Liters
or M1V1=M2V2 for dilutions.
Usually, just see which variables you have and manipulate the equations to determine the value you are looking for.
by Parsamokhtar
Tue Nov 26, 2019 3:36 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Oxidation state
Replies: 3
Views: 19

Re: Oxidation state

Oxidation states are basically the charge of different ions. They usually align with the group number of the atom, but for transition metals, they vary.
by Parsamokhtar
Mon Nov 18, 2019 2:18 pm
Forum: Dipole Moments
Topic: Dipole moments
Replies: 4
Views: 21

Re: Dipole moments

From the positive to the negative charge. Within a bond, not the entire molecule.
by Parsamokhtar
Mon Nov 18, 2019 2:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bonds in VSEPR
Replies: 11
Views: 45

Re: Bonds in VSEPR

Double and Triple bonds are accounted for in the same way that single bonds are: as a single bonding group/domain.
by Parsamokhtar
Mon Nov 18, 2019 2:15 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.1
Replies: 1
Views: 8

2E.1

2E. 1
for this question I thought the structure in part a (bent) must have a lone pair, but on the manual it says that it may have lone pairs. I don't understand how.
by Parsamokhtar
Mon Nov 18, 2019 2:13 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: H-bonds: 3F.5 (b)
Replies: 2
Views: 12

Re: H-bonds: 3F.5 (b)

The first molecule has a hydrogen attached to an Oxygen (one of the three atoms that make hydrogen bonding possible). diethyl ether doesn't have a hydrogen bonded to either N, O or F so it cannot exhibit hydrogen bonding
by Parsamokhtar
Mon Nov 18, 2019 2:12 pm
Forum: Student Social/Study Group
Topic: Test 2 Study Worksheets
Replies: 9
Views: 184

Re: Test 2 Study Worksheets

I think they might give us one during the peer review session.
by Parsamokhtar
Mon Nov 11, 2019 1:42 am
Forum: Dipole Moments
Topic: Hydrogen bonds
Replies: 17
Views: 78

Re: Hydrogen bonds

H bonds can only form with these three atoms.
by Parsamokhtar
Mon Nov 11, 2019 1:41 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Anions
Replies: 7
Views: 24

Re: Anions

no most metals are cations and will have polarizing power, not be polarizable.
by Parsamokhtar
Mon Nov 11, 2019 1:41 am
Forum: Electronegativity
Topic: dipole moments
Replies: 7
Views: 21

Re: dipole moments

Yes, the larger the difference in electronegativity the stronger the dipole moments of the molecule are.
by Parsamokhtar
Mon Nov 11, 2019 1:40 am
Forum: Bond Lengths & Energies
Topic: Size
Replies: 9
Views: 28

Re: Size

The larger the size of the atoms, the more likely their bond length will be greater.
by Parsamokhtar
Mon Nov 11, 2019 1:40 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs and Molecular Shape
Replies: 3
Views: 13

Re: Lone Pairs and Molecular Shape

The other atoms will be repelled by the lone electrons. The bonds between the central atom and peripheral ones contain negatively charged electrons which will tend to move as far as possible from the concentrated negative charge of the unpaired e-.
by Parsamokhtar
Sun Nov 10, 2019 4:48 pm
Forum: Lewis Structures
Topic: Oxygen
Replies: 8
Views: 36

Re: Oxygen

The first electron being removed from oxygen comes out of a full orbital. The electron-electron repulsion of the two e- decreases the magnitude of the force of the nucleus these electrons experience, decreasing the energy necessary to remove them from the atom.
by Parsamokhtar
Sun Nov 10, 2019 4:46 pm
Forum: Dipole Moments
Topic: Polarity
Replies: 8
Views: 28

Re: Polarity

The greater difference in the electronegativity between two atoms, the more polar the bond between them will be because the more electronegative atom will have a greater pull on the electrons, and that side of the bond will be more negative.
by Parsamokhtar
Sun Nov 10, 2019 4:45 pm
Forum: Bond Lengths & Energies
Topic: Bond strength
Replies: 4
Views: 19

Re: Bond strength

Yes, single bonds are the weakest and longest, triple bonds are the shortest and strongest. Also, atomic radius comes into play. Smaller atoms tend to be closer and more strongly held together.
by Parsamokhtar
Sun Nov 10, 2019 4:44 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: D Subshell
Replies: 7
Views: 46

Re: D Subshell

10 electrons. The d subshell has 5 orbitals, each able to hold one pair, or two electrons, adding up to a max of 10 e-.
by Parsamokhtar
Sun Nov 10, 2019 4:43 pm
Forum: Lewis Structures
Topic: Midterm grades
Replies: 26
Views: 194

Re: Midterm grades

I think we should have the grades by Wednesday.
by Parsamokhtar
Mon Nov 04, 2019 9:53 pm
Forum: Ionic & Covalent Bonds
Topic: Bond Lengths
Replies: 4
Views: 33

Re: Bond Lengths

Calculating bond length is just adding the radii of the two atoms bonded.
by Parsamokhtar
Mon Nov 04, 2019 9:53 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 4s or 3d first?
Replies: 14
Views: 88

Re: 4s or 3d first?

The 4s shell is filled first, any energy level that is higher is always filled first. But you write it second because it has higher energy and if any electron is removed from the atom it's removed from a higher energy shell first>
by Parsamokhtar
Mon Nov 04, 2019 9:44 pm
Forum: SI Units, Unit Conversions
Topic: Unit Conversion
Replies: 2
Views: 34

Re: Unit Conversion

I think you can provide the answer anyway, but sometimes it makes it easier to count sig figs when changing the units.
by Parsamokhtar
Mon Nov 04, 2019 9:42 pm
Forum: Lewis Structures
Topic: Double Bonds
Replies: 3
Views: 20

Re: Double Bonds

Using formal charges can help with this. A double bonded O with two lone pairs would have a formal charge of zero, whereas if it had a single bond with three unpaired e- the formal charge would be -1, which is unfavorable. The same thing goes for F.
by Parsamokhtar
Mon Nov 04, 2019 9:41 pm
Forum: Resonance Structures
Topic: Resonance
Replies: 2
Views: 19

Re: Resonance

Yes but there can also be multiple structures with different formal charges. It's mostly dependent on the fact that double or triple bonds can be distributed to other bonds between the same to atoms in a molecule.
by Parsamokhtar
Mon Oct 28, 2019 8:57 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Drawing Lewis Structures
Replies: 5
Views: 50

Re: Drawing Lewis Structures

molecules with resonance, or those having atoms with expanded octets would be exceptions to bonding rules and the octet rule.
by Parsamokhtar
Mon Oct 28, 2019 8:56 pm
Forum: Properties of Light
Topic: Midterm formulas
Replies: 6
Views: 64

Re: Midterm formulas

I think we get all the information we had ont he 1st test.
by Parsamokhtar
Mon Oct 28, 2019 8:55 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Losing electrons
Replies: 3
Views: 24

Re: Losing electrons

3d fills up after 4s but 4s would still have higher energy because it is in the fourth energy level. Electrons are removed from the outermost/highest energy levels/shells.
by Parsamokhtar
Mon Oct 28, 2019 8:54 pm
Forum: Resonance Structures
Topic: Resonance Clarification
Replies: 8
Views: 42

Re: Resonance Clarification

A molecule/compound has resonance when there can be a double/triple bond placed at multiple bond sites without changing the orientation or atoms bonded.
by Parsamokhtar
Mon Oct 28, 2019 8:53 pm
Forum: Ionic & Covalent Bonds
Topic: grading
Replies: 5
Views: 57

grading

does anyone know how to check our grade in the class?
by Parsamokhtar
Mon Oct 21, 2019 12:54 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Kinetic Energy
Replies: 4
Views: 32

Re: Kinetic Energy

Kinetic energy is zero when the work function iis equal to the energy of the photon hitting the metal. If a problem asks how much energy is required to eject an electron from a surface of the metal you would also make KE equal to zero.
by Parsamokhtar
Mon Oct 21, 2019 12:52 pm
Forum: Trends in The Periodic Table
Topic: Isoelectronic Atoms
Replies: 6
Views: 46

Re: Isoelectronic Atoms

Isoelectronic atoms have the same number of electrons but one is an ion of some sorts and the two behave chemically differently. For example, F- and Ne both have 10 electrons, but behave differently when it comes to bonding, chemical reactions, etc....
by Parsamokhtar
Mon Oct 21, 2019 12:50 pm
Forum: Ionic & Covalent Bonds
Topic: Boiling Point
Replies: 4
Views: 330

Re: Boiling Point

For this, you would probably have to see which has a stronger type of intermolecular bonds, the stronger the bond between molecules, the more energy would be required to sever them, which would lead that molecule/compound to have a higher boiling point.
by Parsamokhtar
Mon Oct 21, 2019 11:22 am
Forum: Photoelectric Effect
Topic: KE energy & intensity
Replies: 5
Views: 27

Re: KE energy & intensity

The fact that increasing the frequency is what determined electrons being ejected or not showed the particle aspects of light. The intensity of light would just be shining more of the same frequency light on the metal, but increasing frequency increased energy and herefore emitted electrons from the...
by Parsamokhtar
Mon Oct 21, 2019 11:16 am
Forum: Properties of Light
Topic: calculating frequency of light
Replies: 4
Views: 32

Re: calculating frequency of light

Yes you assume that KE is zero because that will make the energy of the photon equal to the work function.
by Parsamokhtar
Fri Oct 18, 2019 2:23 pm
Forum: Student Social/Study Group
Topic: Final Jitters
Replies: 90
Views: 19201

Re: Final Jitters

I usually meditate, and work out. and get a lot of sleep.
by Parsamokhtar
Fri Oct 18, 2019 2:21 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 4
Views: 24

Re: Rydberg Equation

You use rydberg's equation if you need to calculate the energy level of a hydrogen atom. at any level equal to n.
by Parsamokhtar
Fri Oct 18, 2019 2:20 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Best Way To Study?
Replies: 56
Views: 250

Re: Best Way To Study?

I usually just review my notes until I understand the concepts. Then go through the suggested problems in the syllabus and make sure I can do all of them.
by Parsamokhtar
Fri Oct 18, 2019 2:19 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect
Replies: 6
Views: 29

Re: Photoelectric Effect

The electron would move to the surface of the metal, but because in the experiment the detector that records the KE of electrons has a positive charge the electron would be pulled away by charge of the detector.
by Parsamokhtar
Fri Oct 18, 2019 2:17 pm
Forum: Quantum Numbers and The H-Atom
Topic: Ground State [ENDORSED]
Replies: 5
Views: 61

Re: Ground State [ENDORSED]

In a ground state, the electrons of an atom occupy their lowest energy levels possible.
by Parsamokhtar
Sun Oct 13, 2019 6:38 pm
Forum: Molarity, Solutions, Dilutions
Topic: M1V1=M2V2
Replies: 11
Views: 97

Re: M1V1=M2V2

You use this equation during dilution questions. like when you're asked how much of one solution you would need to achieve certain molarity of another volume solution. Anytime you'd be given three of the variables of the equation and asked to find the other.
by Parsamokhtar
Sun Oct 13, 2019 6:36 pm
Forum: Properties of Light
Topic: Next test
Replies: 23
Views: 152

Re: Next test

Im pretty sure the information provided to us the first test is what we're given every time.
by Parsamokhtar
Sun Oct 13, 2019 6:34 pm
Forum: Limiting Reactant Calculations
Topic: About Finding Limiting Reactant
Replies: 7
Views: 46

Re: About Finding Limiting Reactant

You can leave it in either moles or grams. Unless the question itself asks for either grams or moles.
by Parsamokhtar
Sun Oct 13, 2019 6:32 pm
Forum: Properties of Light
Topic: Photoelectric Effect
Replies: 7
Views: 29

Re: Photoelectric Effect

any other molecules may interfere with the light and scatter the frequencies making the data less accurate.
by Parsamokhtar
Sun Oct 13, 2019 6:31 pm
Forum: Properties of Light
Topic: Manipulation of Equations
Replies: 6
Views: 25

Re: Manipulation of Equations

the -1 exponent just means the lambda is in the denominator.
by Parsamokhtar
Wed Oct 02, 2019 10:58 pm
Forum: Ideal Gases
Topic: Module Questions- Balancing Equations
Replies: 4
Views: 65

Re: Module Questions- Balancing Equations

4C4H10 +26O2(g) ---> 16CO2(g) + 20H2O(g)
you just balance the equation with 4 as the prefix for C4H10 and then count the moles of gas on both sides and count the ones on the right and subtract he moles of gas on the left. so for this it would be 16 + 20 - 26 = 10 moles of gas net.
by Parsamokhtar
Wed Oct 02, 2019 4:24 pm
Forum: Significant Figures
Topic: Quick General Question!
Replies: 5
Views: 70

Re: Quick General Question!

You should round it based on the 1st digit that wouldn't be included due to sig figs. So in this case 4.696 would be rounded to 4.70.
by Parsamokhtar
Wed Oct 02, 2019 4:22 pm
Forum: Significant Figures
Topic: E21b. Sig Figs
Replies: 5
Views: 53

Re: E21b. Sig Figs

it depends on the number of sig figs used for when you calculate molar mass.
by Parsamokhtar
Tue Oct 01, 2019 3:59 pm
Forum: Significant Figures
Topic: Question about significant figures and rounding a number
Replies: 4
Views: 52

Re: Question about significant figures and rounding a number

5.4545454545 would be 5, 5.5, 5.45, and 5.455 for 1, 2, 3 and 4 sig figs respectively.
5.55555555 would be 6, 5.6, 5.56, and 5.556 for 1, 2, 3 and 4 sig figs respectively.
by Parsamokhtar
Tue Oct 01, 2019 3:55 pm
Forum: Limiting Reactant Calculations
Topic: HW problem L1
Replies: 3
Views: 33

Re: HW problem L1

start with .3 mol CLO2 multiply by 1 mol Br2/6 mol ClO2, which will give you the moles of Br2 yielded. To find the mass of that amount of moles just multiply it by the molar mass.

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