Search found 53 matches

by Nyari Muchaka_Discussion 4A
Mon Dec 02, 2019 9:29 pm
Forum: Identifying Acidic & Basic Salts
Topic: Electron withdrawing to identify acids
Replies: 2
Views: 41

Re: Electron withdrawing to identify acids

Electron withdrawing applies to an electronegative atom. The more electronegative an atom is in a molecule, it will pull more strongly on the electrons. This will cause electron delocalization and the concentration of a negative charge around the electronegative atom allows hydrogen to gain a more p...
by Nyari Muchaka_Discussion 4A
Mon Dec 02, 2019 9:27 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Stronger Acid than another
Replies: 5
Views: 47

Re: Stronger Acid than another

The molecules are identical except one has three chlorine and the other three hydrogens. Since chlorine is more electronegative ti will pull more strongly on the electrons and thus create a more stable molecule through electron delocalization. As chlorine pull on the electrons, the hydrogen becomes ...
by Nyari Muchaka_Discussion 4A
Mon Dec 02, 2019 9:20 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pOH
Replies: 6
Views: 77

Re: pOH

The calculations for pOH are the same as for pH including the trend, high kA and low pKA indicate a strong base.
by Nyari Muchaka_Discussion 4A
Mon Dec 02, 2019 9:17 pm
Forum: Lewis Acids & Bases
Topic: Acidic or Basic
Replies: 3
Views: 58

Re: Acidic or Basic

Most household cleaners are basic(bleach, soap) while citric based fruits and vinegar tend to be acidic.
by Nyari Muchaka_Discussion 4A
Tue Nov 26, 2019 12:08 am
Forum: Lewis Acids & Bases
Topic: When is an acid considered Bronsted?
Replies: 9
Views: 100

Re: When is an acid considered Bronsted?

Bronsted has to do with protons(more protons means more acidic). A Bronsted acid is a proton donor(HCl donates H+) and the Bronsted base is a proton acceptor. Lewis has to do with electrons, a Lewis acid is an electron acceptor and a Lewis base is an electron donor. All Bronsted acids are Lewis acid...
by Nyari Muchaka_Discussion 4A
Tue Nov 26, 2019 12:05 am
Forum: Sigma & Pi Bonds
Topic: sigma and pi bonds
Replies: 19
Views: 336

Re: sigma and pi bonds

Yes, all single bonds are sigma as single bonds are the weakest and thus have the most room for rotation and movement. Double and triple bonds are stronger and thus resist movement hence making them pi bonds.
by Nyari Muchaka_Discussion 4A
Tue Nov 26, 2019 12:01 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Transition Metals
Replies: 4
Views: 60

Re: Transition Metals

It can happen with any atom that acts as a Lewis Base(electron acceptor) which is mainly the transition metals.
by Nyari Muchaka_Discussion 4A
Mon Nov 25, 2019 11:59 pm
Forum: Trends in The Periodic Table
Topic: Ionic Radius
Replies: 5
Views: 129

Re: Ionic Radius

All three of those atoms essentially copy the orientation of Argon as they have gained electrons in order to satisfy the octet rule. However, since they have gained electrons but keep the same number of protons, the positive charge is spread out more over the atom with each additional negative char...
by Nyari Muchaka_Discussion 4A
Mon Nov 25, 2019 11:57 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Number
Replies: 3
Views: 33

Re: Coordination Number

The coordination number is the number of ligands bonded to a transition metal. So if the molecule is octahedral, it has six bonds and thus the coordination number is six. An easy way to tell is to count the number of ligands in the brackets(atoms outside the bracket do not directly bond to the centr...
by Nyari Muchaka_Discussion 4A
Mon Nov 25, 2019 11:55 pm
Forum: Sigma & Pi Bonds
Topic: Unhybridized Orbital vs Spin Pair?
Replies: 8
Views: 52

Re: Unhybridized Orbital vs Spin Pair?

Unhybridized, electrons prefer to be in their own space before pairing due to the repulsion of the negative charge.
by Nyari Muchaka_Discussion 4A
Mon Nov 25, 2019 11:52 pm
Forum: Naming
Topic: -ate ending
Replies: 8
Views: 81

Re: -ate ending

When the complex in brackets has an overall negative charge, the transition metal will end in ate, I.E. oxalate
by Nyari Muchaka_Discussion 4A
Mon Nov 25, 2019 11:51 pm
Forum: Naming
Topic: Order of Ligands
Replies: 4
Views: 52

Re: Order of Ligands

When naming the compound the ligands(the atoms in the brackets) are named in alphabetical order. When writing the chemical formula itself, the order of the ligands does not matter.
by Nyari Muchaka_Discussion 4A
Mon Nov 18, 2019 6:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Length
Replies: 9
Views: 99

Re: Test 2 Length

My TA told me the study VSEPR, how bond dipole moments are used to determine polarity, why lone pairs are more likely to be found in certain places and how that placement affects bonding in an atom, intermolecular forces with cations and anions, and sigma and pi bonds. I believe test two is the same...
by Nyari Muchaka_Discussion 4A
Mon Nov 18, 2019 6:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: resonance structures in molecular structures
Replies: 4
Views: 35

Re: resonance structures in molecular structures

Resonance structures would not matter as the molecule still maintains the same number of electron density regions based on repulsion forces and the same number of bonds formed is also maintained. The places in which the electron density would change but the bond angles would still be maintained in t...
by Nyari Muchaka_Discussion 4A
Mon Nov 18, 2019 6:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond angles
Replies: 2
Views: 30

Re: Bond angles

Both the shape which is AX2(just based on bonds and arrangement which is AX2E3(based on bonds and lone pairs) would be linear.
by Nyari Muchaka_Discussion 4A
Mon Nov 18, 2019 6:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sigma and Pi Bonds
Replies: 2
Views: 32

Re: Sigma and Pi Bonds

They may also ask if the bonds can be rotated based on the presence of a sigma or pi bonds.
by Nyari Muchaka_Discussion 4A
Mon Nov 18, 2019 6:49 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability
Replies: 2
Views: 106

Re: Polarizability

Bigger atoms have more electrons and thus have the ability to create stronger dipole charges(partial negatives and partial positives) due to the presence of more charges (more electrons).
by Nyari Muchaka_Discussion 4A
Mon Nov 11, 2019 6:28 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: forces and boiling points
Replies: 6
Views: 32

Re: forces and boiling points

Since chlorine has more electrons, it is able to establish a stronger dipole force between the atoms and thus the bonding is stronger in CCL4. Thus, this molecule requires more energy to break the strong bonds, thus increasing the boiling point.
by Nyari Muchaka_Discussion 4A
Mon Nov 11, 2019 6:25 pm
Forum: DeBroglie Equation
Topic: Velocity
Replies: 13
Views: 316

Re: Velocity

If this is based on the Heisenberg Indeterminacy Equation then if the velocity is larger than the speed of light you must assume you have been given an incorrect atomic model which goes to prove that the mass of an atom has to be a certain size or larger in order to properly abide by the laws of the...
by Nyari Muchaka_Discussion 4A
Mon Nov 11, 2019 6:19 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Magnetic Quantum numbers
Replies: 13
Views: 269

Re: Magnetic Quantum numbers

The magnetic quantum number is dependent on the angular momentum number. The angular momentum number or L determines the magnetic quantum number as it is -L to +L, so if L=3 then the magnetic quantum number can be -3,-2,-1,0,1,2,3.
by Nyari Muchaka_Discussion 4A
Mon Nov 11, 2019 6:16 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: Hydrogen bonding
Replies: 5
Views: 50

Re: Hydrogen bonding

Hydrogen bonds are only formed with N,O, and F as they are the most electronegative elements. Bonds formed between hydrogen and other molecules will be too weak to classify as a hydrogen bond.
by Nyari Muchaka_Discussion 4A
Mon Nov 11, 2019 6:13 pm
Forum: Student Social/Study Group
Topic: Chem 14B
Replies: 10
Views: 139

Re: Chem 14B

I heard 14BL is best to take with 14C as BL is the lab version of B so once you know all the information from 14B you are more easily able to succeed in 14BL. Also, don't forget that you have to take 30A before you can take 14B and need to take 30B either at the same time as 14B or before taking it.
by Nyari Muchaka_Discussion 4A
Mon Nov 04, 2019 9:31 pm
Forum: Trends in The Periodic Table
Topic: electron affinity
Replies: 4
Views: 55

Re: electron affinity

All atoms want to be stable and have a full valence shell. Thus, some atoms will try to share or take electrons from other atoms, and other atoms will try to give their's away to empty the valence shell and keep the next level valence shell filled. When an atom gains an electron, it becomes more sta...
by Nyari Muchaka_Discussion 4A
Mon Nov 04, 2019 9:27 pm
Forum: Resonance Structures
Topic: 2B.15
Replies: 1
Views: 48

Re: 2B.15

Nitrogen cannot form a double bond with both oxygen and a single bond with chlorine as that forms a total of five bonds(10 shared electrons), and nitrogen does not have the ability to expand past the octet rule(can only take on eight electrons). Atoms in row three and below can do this as they have ...
by Nyari Muchaka_Discussion 4A
Mon Nov 04, 2019 9:18 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 4s or 3d first?
Replies: 14
Views: 298

Re: 4s or 3d first?

On the periodic table the 4s comes before the 3d. But on the test you write it out in terms of energy subshells. So when you write your final answer 3d should be first because the 3d shell comes before the 4s shell as it is a lower energy level(go in ascending order of the numbers), it is just not d...
by Nyari Muchaka_Discussion 4A
Mon Nov 04, 2019 9:16 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Atomic Orbitals
Replies: 2
Views: 118

Re: Atomic Orbitals

It's like Heisenberg's uncertainty principle. You describe each orbital based on the probability or chance you will find an electron located there.
by Nyari Muchaka_Discussion 4A
Mon Nov 04, 2019 9:15 pm
Forum: Ionic & Covalent Bonds
Topic: Bond Lengths
Replies: 4
Views: 61

Re: Bond Lengths

There is a table in the textbook with bond lengths that will most likely be provided.
by Nyari Muchaka_Discussion 4A
Mon Oct 28, 2019 9:30 pm
Forum: Octet Exceptions
Topic: aufbau principle
Replies: 8
Views: 105

Re: aufbau principle

When you go across the periodic table you come across 3d after 4s, however, in terms of energy levels, you go in numerical order so since 3 is before 4, 3d is lower than 4s. Also pretty sure Lavelle wants us to write the configuration in terms of ascending energy levels.
by Nyari Muchaka_Discussion 4A
Mon Oct 28, 2019 9:23 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 4
Views: 57

Re: Formal Charge

The safest bet is to do formal charge calculations for all your structures. However, this is more necessary for those atoms as they have a d-orbital, and are thus able to hold more than eight electrons versus the atoms without the d orbital who adhere to the octet rule. Any atom above period 3 has a...
by Nyari Muchaka_Discussion 4A
Mon Oct 28, 2019 9:20 pm
Forum: Trends in The Periodic Table
Topic: Ionic Radius
Replies: 5
Views: 129

Re: Ionic Radius

All three of those atoms essentially copy the orientation of Argon as they have gained electrons in order to satisfy the octet rule. However, since they have gained electrons but keep the same number of protons, the positive charge is spread out more over the atom with each additional negative charg...
by Nyari Muchaka_Discussion 4A
Mon Oct 28, 2019 9:17 pm
Forum: Trends in The Periodic Table
Topic: s-block vs p-block
Replies: 5
Views: 1068

Re: s-block vs p-block

The s block is on the left side of the periodic table and the p block on the right side. Since ionization energy increases from left to right, the s block is more willing to give up their electrons due to their lower ionization energy in comparison to p. Thus, the s orbital is more reactive in that ...
by Nyari Muchaka_Discussion 4A
Mon Oct 28, 2019 9:14 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Octet Rules
Replies: 8
Views: 87

Re: Octet Rules

Octet rule basically means that atoms are more stable when they have a full valence electron. In the s orbital, electrons can fit two electrons, in the p orbitals, the atom can fit six electrons, in the d orbital ten electrons, and in the f orbital 14 electrons. All atoms after beryllium have both a...
by Nyari Muchaka_Discussion 4A
Tue Oct 22, 2019 10:08 pm
Forum: *Particle in a Box
Topic: cations and anions
Replies: 5
Views: 158

Re: cations and anions

When ionic bonds are made a highly electronegative atom is bonding with an atom of less electronegativity. This essentially means one atom wants electrons more than the other atoms in order to fill its valence shell and become more stable. Thus, this atom will steal electrons from the atom it bonds ...
by Nyari Muchaka_Discussion 4A
Tue Oct 22, 2019 10:05 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration
Replies: 4
Views: 53

Re: Electron Configuration

It just refers to where the electron is placed. The p orbital can fir six electrons and has three orbitals(x,y,z). Electrons will occupy each individual orbital first before pairing up. In your example, there are three electrons in the p orbital, thus each electron will occupy a separate orbital fro...
by Nyari Muchaka_Discussion 4A
Tue Oct 22, 2019 10:02 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Spin
Replies: 8
Views: 77

Re: Electron Spin

The easiest way to do this is to draw out the orbitals. For example, p has three orbitals that can fit six electrons. If you are in the p orbital draw out three lines. Now say you have four electrons in the p orbital, first draw one electron on each line all spinning upwards. The fourth electron wil...
by Nyari Muchaka_Discussion 4A
Tue Oct 22, 2019 9:59 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Atomic radius vs. Ionic radius
Replies: 5
Views: 50

Re: Atomic radius vs. Ionic radius

Atomic radius is half the distance between the center of two linked atoms(covalently bonded). Ionic radius is different due to the nature of the bond. Ionic bonds involve the interaction of a cation and an anion(one steals electrons the other loses it), and thus the distance between these two molecu...
by Nyari Muchaka_Discussion 4A
Tue Oct 22, 2019 9:56 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: l values
Replies: 4
Views: 81

Re: l values

It also goes up to g and h values however in class we only went up to f and l=3. If your n is greater than 4, your l value can possibly be greater than 4. I.E. n=5 so l can be 0,1,2,3,4.
by Nyari Muchaka_Discussion 4A
Mon Oct 14, 2019 9:34 pm
Forum: Photoelectric Effect
Topic: Question about Energy Threshold
Replies: 7
Views: 85

Re: Question about Energy Threshold

The electron only jumps orbitals if the energy of the photon reaches the energy threshold(exactly how much energy is required to excite the electron), or is greater than the energy threshold. Increasing the intensity or wavelength of light will not result in the electron being excited because these ...
by Nyari Muchaka_Discussion 4A
Mon Oct 14, 2019 9:30 pm
Forum: Properties of Electrons
Topic: calculating frequency
Replies: 3
Views: 53

Re: calculating frequency

Frequency measures the number of times a wave passes through a given point in a given amount of time. Given that fact, frequency cannot be negative as you cannot have a negative number of waves. If you are getting a negative frequency, you can check and see if maybe there are negative on both sides ...
by Nyari Muchaka_Discussion 4A
Mon Oct 14, 2019 9:27 pm
Forum: Student Social/Study Group
Topic: De Broglie and Heseinberg
Replies: 2
Views: 45

De Broglie and Heseinberg

In class were we given a constant for an electron's velocity and/or mass? Just wondering for usage in the De Broglie and Heisenberg equations.
by Nyari Muchaka_Discussion 4A
Mon Oct 14, 2019 9:23 pm
Forum: Properties of Electrons
Topic: atomic spectroscopy
Replies: 5
Views: 54

Re: atomic spectroscopy

Yes, each element has a unique light spectrum. As the excited electrons jump down from orbitals, they emit waves and these waves are perceived as colors depending on their wavelength. These colors can then be matched to specific elements and used to identify them. Each element when these wavelengths...
by Nyari Muchaka_Discussion 4A
Mon Oct 14, 2019 9:17 pm
Forum: Einstein Equation
Topic: E=hv
Replies: 43
Views: 3738

Re: E=hv

E=hv is to find the energy of a photon(light) and is usually coupled with the c=lambdaxvelocity because c represents the speed of light. When combined these two equations create the E=hc/lambda equation. If you want to find the energy contained in an electron, you would use the De Broglie equation a...
by Nyari Muchaka_Discussion 4A
Sun Oct 13, 2019 6:37 pm
Forum: Photoelectric Effect
Topic: Energy of Photon Clarification
Replies: 4
Views: 101

Re: Energy of Photon Clarification

Since the electrons require a specific threshold of energy in order to be ejected, the energy or photon hitting the electron has to be greater than or at least equal to the amount of work needed to eject it.
by Nyari Muchaka_Discussion 4A
Sun Oct 13, 2019 6:30 pm
Forum: Properties of Light
Topic: Photoelectric Effect
Replies: 7
Views: 67

Re: Photoelectric Effect

Vacuums are useful for reducing the number of molecules in a chamber(such as air or water vapor) so that the results of the test are more accurate and now skewed by environmental interference. It also makes it easier to measure smaller molecules such as electrons or ions as they travel within the va...
by Nyari Muchaka_Discussion 4A
Sun Oct 13, 2019 6:28 pm
Forum: Properties of Light
Topic: Next test
Replies: 23
Views: 340

Re: Next test

The equation sheet we got on the first test will be the same one provided for all future tests.
by Nyari Muchaka_Discussion 4A
Sun Oct 13, 2019 6:27 pm
Forum: Properties of Light
Topic: Manipulation of Equations
Replies: 6
Views: 50

Re: Manipulation of Equations

You should be getting the same answer. Make sure you move the negative exponent to the bottom before calculating because you technically cannot calculate a number to the negative power.
by Nyari Muchaka_Discussion 4A
Sun Oct 13, 2019 6:25 pm
Forum: Administrative Questions and Class Announcements
Topic: How to check how many points I have this week for posting on Chemistry Community?
Replies: 11
Views: 126

Re: How to check how many points I have this week for posting on Chemistry Community?

You should ask your RA. Grades should be on MyUCLA underclasses, then exam and homework grades. My RA told me I won't be able to see any of my homework grades until they are all put in so I am going to keep track of them myself.
by Nyari Muchaka_Discussion 4A
Thu Oct 03, 2019 5:22 pm
Forum: Empirical & Molecular Formulas
Topic: Calculating Empirical Formula with Given Amounts of Each Element
Replies: 7
Views: 77

Re: Calculating Empirical Formula with Given Amounts of Each Element

No, you do not have to, the 100g method just makes it easier to check the work and execute the problem.
by Nyari Muchaka_Discussion 4A
Thu Oct 03, 2019 5:18 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity
Replies: 9
Views: 113

Re: Molarity

Molarity is used to calculate the concentration of of molecules in a solution. It is useful when you want to find the strength of a solution or when you are given a question asking you to dilute a solution and need to use the MV(initial)=MV(final) equation.
by Nyari Muchaka_Discussion 4A
Thu Oct 03, 2019 5:08 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Lab experiments- accuracy vs precision
Replies: 7
Views: 129

Re: Lab experiments- accuracy vs precision

With a lab experiment, when your results are close to the actual answer they can be described as accurate. If you do the lab multiple times and your results for each test are close together then the results can be defined as precise. If lab results are precise but not accurate, it could mean some pa...
by Nyari Muchaka_Discussion 4A
Thu Oct 03, 2019 5:03 pm
Forum: Balancing Chemical Reactions
Topic: H.1 Chemical Principle 7th edition
Replies: 4
Views: 88

Re: H.1 Chemical Principle 7th edition

Matter cannot be created or destroyed so if oxygen isn't present(on its own) in the reactant side if cannot just show up on the product side. Hence why we balance equations, to ensure the same number of reactants is present in the products.
2Cu +SO2-> 2CuO +S
by Nyari Muchaka_Discussion 4A
Thu Oct 03, 2019 4:50 pm
Forum: Limiting Reactant Calculations
Topic: Question M.1 [ENDORSED]
Replies: 5
Views: 1097

Re: Question M.1 [ENDORSED]

Since ammonia is the limiting reactant you have to convert from moles of ammonia to moles of hydrazine. 1. 35g/17.04(molar mass of ammonia)=2.054mol of ammonia. Since ammonia and hydrazine are in a two to one ratio you use the mol of ammonia to calculate the mol fo hydrazine. 2. 2.054/2 is 1.0269 mo...

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