## Search found 79 matches

Thu Jan 14, 2021 8:30 am
Forum: Ideal Gases
Topic: T variable in pv=nrt [ENDORSED]
Replies: 36
Views: 250

### Re: T variable in pv=nrt[ENDORSED]

T is always in Kelvin because the gas constant r has a kelvin unit in it.
Thu Jan 14, 2021 8:29 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Week 2 Sapling #9
Replies: 4
Views: 22

### Re: Week 2 Sapling #9

The direction you do it in results in reciprocal values of Kc. This is because Kc would be flipped if reversed. However, the question asks for the Kc related to the forward reaction.
Thu Jan 14, 2021 8:23 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE
Replies: 7
Views: 21

### Re: ICE

You can use ICE charts when finding how much a concentration changed when going to equilibrium, which allows you to find al of the equilibrium concentrations, and then calculate Kc using that.
Thu Jan 14, 2021 8:20 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pH and pKa
Replies: 6
Views: 26

### Re: pH and pKa

An easy way to think about it would be to think of p as a modifier that states the relative amount of things that are released. pH is then a measure of the number of H3O+ ions that are created when something dissolves. pKa would be the measure of the relative number of disassociations that happen wh...
Thu Jan 14, 2021 8:10 am
Forum: Ideal Gases
Topic: n/V = concentration
Replies: 13
Views: 55

### Re: n/V = concentration

As n is the number of moles and V is volume in liters, it is easy to see that n/V is just molarity, which is a measure of concentration.
Sun Jan 10, 2021 3:21 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Clarification of terminology
Replies: 15
Views: 67

### Re: Clarification of terminology

yes, i think what shifting refers to is when a change occurs in Q, the reaction's equilibrium point has to shift to accommodate it.
Sun Jan 10, 2021 3:17 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Delta H and its affect
Replies: 5
Views: 19

### Re: Delta H and its affect

H is enthalpy. A positive delta H means that enthalpy is increasing due to increase in energy (endothermic) and the opposite is doe to a decrease (exothermic) in the system. Energy is drawn from bond rearrangement and from the environment.
Sun Jan 10, 2021 3:15 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Are there reactions that just do not/ can not ever reach equilibrium?
Replies: 18
Views: 48

### Re: Are there reactions that just do not/ can not ever reach equilibrium?

One way reactions are usually the reactions that can't do this. However, just because they are denoted as going in one way does not mean that they can never go back. It's just that the conditions needed to be met are almost never possible.
Sun Jan 10, 2021 3:13 pm
Forum: Ideal Gases
Topic: Non-Ideal gases?
Replies: 22
Views: 84

### Re: Non-Ideal gases?

I do not think we will be learning about real gases and the modified ideal gas equation in this series of courses.
Sun Jan 10, 2021 3:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Concentration
Replies: 12
Views: 35

### Re: Concentration

You cant have negative moles of something, it just doesn't make sense. Concentration is moles/liters, so either of the two things have to be negative for a negative concentration, which is impossible.
Sun Jan 10, 2021 3:10 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: What are the small elements over the equilibrium symbols?
Replies: 5
Views: 25

### Re: What are the small elements over the equilibrium symbols?

These are catalysts, which are need for the reaction to proceed but aren't consumed. Sometimes, you'll see a capital delta symbol, which means that heat is being infused to make that reaction go forward.
Wed Dec 09, 2020 5:36 pm
Forum: Naming
Topic: Ferrate
Replies: 7
Views: 62

### Re: Ferrate

It depends on the charge of the overall coordination ion. If it is a positively charged ion, you use ferrate and not ironate. Negatively charge: use iron, not ironate or ferrate.
Wed Dec 09, 2020 5:33 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH of acidic ions
Replies: 2
Views: 13

### Re: pH of acidic ions

The NH4Cl disassociates and then the NH4+ turns into an NH3 and an H+. The Cl- doesn't do anything else in the solution because there being nothing for it to bond to. pH is only influenced by [H+] so the Cl- doesn't matter.
Wed Dec 09, 2020 5:30 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: CCl4 polarity
Replies: 2
Views: 14

### Re: CCl4 polarity

CCl4 is actually nonpolar, but it has 4 dipole moments in the molecule. These dipole moments cancel out, resulting in a nonpolar molecule.
Wed Dec 09, 2020 5:27 pm
Forum: Bronsted Acids & Bases
Topic: Textbook 6A.13
Replies: 2
Views: 12

### Re: Textbook 6A.13

Remember that lewis acids and bases involve electron pairs. Bases are those with electron pairs that can be donated, while acids are the acceptors.
Wed Dec 09, 2020 5:26 pm
Forum: Naming
Topic: Aqua vs Hydrate
Replies: 12
Views: 62

### Re: Aqua vs Hydrate

Yes, you are correct. Aqua is when it is part of the coordination sphere, while hydrate is when it is outside the cor=ordination sphere.
Sun Dec 06, 2020 1:06 pm
Forum: Naming
Topic: Order of Ligands/naming
Replies: 28
Views: 128

### Re: Order of Ligands/naming

Alphabetical order without taking prefixes into account.
Thu Dec 03, 2020 4:25 pm
Forum: Naming
Topic: Sapling Q1
Replies: 20
Views: 176

### Re: Sapling Q1

It should be cobalt(III), not cobalt(II), which means its tetraamminechlorocobalt(III) chloride
Wed Dec 02, 2020 9:54 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: how to tell coordination number
Replies: 3
Views: 44

### Re: how to tell coordination number

It is the sum of all the number of binding sites on the ligands as long as the number is or less than 6. For example, [Fe (NH3)2 Cl3] would be 5, 3 from the chloridos and 2 from the ammines.
Wed Dec 02, 2020 9:51 am
Forum: Hybridization
Topic: Question 2F.15
Replies: 6
Views: 71

### Re: Question 2F.15

the hybridization shows what and how many of each orbital is being hybridized. For example, in and sp3 hybridization, there are 4 orbitals and s is one of them. Therefore, the s-character is 1/4 or 25%. Basically, the more non-s orbitals are hybridized, the less s-character there is.
Wed Dec 02, 2020 9:49 am
Forum: Naming
Topic: Topic 9C Question 1 Part C
Replies: 4
Views: 45

### Re: Topic 9C Question 1 Part C

It should be Cobalt, not a carbonyl group because cobalt would be the metal that the complex is formed around.
Wed Dec 02, 2020 9:47 am
Forum: Naming
Topic: Topic 9C Exercises Question 3
Replies: 4
Views: 34

### Re: Topic 9C Exercises Question 3

Yes, you are thinking of it in the right way. Also, you could create the transition element ion and then see how many anions are necessary to make it neutral. Most, if not all, of the transition metals form cations.
Wed Dec 02, 2020 9:42 am
Forum: Naming
Topic: Ferrate
Replies: 7
Views: 62

### Re: Ferrate

Yes, and I believe this is true for the transition metals that have names derived from ancient greek (Fe, Cu, Ag, Au).
Mon Nov 30, 2020 9:34 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: sapling question 7 (homework week 7/8)
Replies: 4
Views: 20

### Re: sapling question 7 (homework week 7/8)

It usually depends on the 3d shape and the electronegativity of the atoms that comprise the molecule. if the electronegativities are imbalanced in 3 dimensions, then the molecule is polar. Else, it is nonpolar.
Mon Nov 30, 2020 9:26 am
Forum: Naming
Topic: chelating ligand
Replies: 7
Views: 71

### Re: chelating ligand

Chelating ligands are those that have flexibility between binding sites and also have multiple binding sites, allowing for them to form at least 2 bonds with the metal cation.
Mon Nov 30, 2020 9:22 am
Forum: Lewis Structures
Topic: Sapling #20
Replies: 7
Views: 36

### Re: Sapling #20

The fact that it is an ion doesn't change its polarity. Another thing is resonance in the structure causing even distributions of all forms of [AsO4]3-.
Mon Nov 30, 2020 9:20 am
Forum: Hybridization
Topic: sp^3
Replies: 8
Views: 45

### Re: sp^3

Most simple molecules are molecules that have carbon, nitrogen, or oxygen as a central atom. This tends to make the electron geometries tetrahedral, therefore implying an sp3 hybridization, just based on how many lone pairs and bonding sites there are on the central atoms.
Mon Nov 30, 2020 9:17 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 5
Views: 25

### Re: Ligands

I am pretty sure that most, if not all, of the transition metals create cations, which means that all ligands must be lewis bases to provide electron pairs for bond formation.
Wed Nov 25, 2020 10:25 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: sigma and pi bonds in p orbital
Replies: 1
Views: 20

### Re: sigma and pi bonds in p orbital

No, I dont think it matters because most of the time, Nitrogen is hybridized.
Wed Nov 25, 2020 10:24 am
Forum: Lewis Structures
Topic: Octet Rule
Replies: 17
Views: 129

### Re: Octet Rule

Its tricky to consider this. Think of sulfur, it can have six bonds and a lone pair to give it 8 in the valence shell. Remember that covalent bonds are shared. Be careful when thinking that a bond means all the electrons in the bond fulfill an octet. Sulfur, nitrogen and other things can have more t...
Wed Nov 25, 2020 10:16 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Reason why lone pairs decrease bond angle
Replies: 7
Views: 45

### Re: Reason why lone pairs decrease bond angle

Think of it like lone pairs being stubby areas of high density while bonds are more narrow and long. the stubby one will push the narrow ones together slightly to make room for itself, therefore making the bond angles smaller.
Wed Nov 25, 2020 10:14 am
Forum: Sigma & Pi Bonds
Topic: Reason for double bonds being sigma/pi
Replies: 2
Views: 20

### Re: Reason for double bonds being sigma/pi

One of the pairs of electrons bonds linearly and the other can no longer bond linearly so they bond in the characteristic "over and under" pi bonds of two electron probabilities.
Wed Nov 25, 2020 10:13 am
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR T-Shaped Molecular Geometry
Replies: 7
Views: 69

### Re: VSEPR T-Shaped Molecular Geometry

In most molecules this applies to, the first locations filled are axial positions. If a third atom takes an equatorial position and the other two equatorial are lone pairs, then the shape is t-shaped.
Wed Nov 25, 2020 10:11 am
Forum: Hybridization
Topic: Aufbau Diagram of sp3d
Replies: 2
Views: 29

### Re: Aufbau Diagram of sp3d

sp3d hybridization and sp3d2 hybridization is what we see in more complex molecules than tetrahedral ones. The first leads to trigonal bipyramidal and other derivatives of that, whereas the second one leads to octahedral and derivatives of octahedral.
Sat Nov 21, 2020 11:04 am
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR labeling
Replies: 3
Views: 33

### Re: VSEPR labeling

VSEPR has two different shape schemes that both have the same shapes within them. One of them uses electrons to shape, and the other uses only the atoms in the molecule. For example, H2O is tetrahedral when looking at the electron density but bent when looking at the molecule itself.
Sat Nov 21, 2020 11:01 am
Forum: Sigma & Pi Bonds
Topic: trans- & cis- Molecules
Replies: 6
Views: 59

### Re: trans- & cis- Molecules

Ethenes are fixed molecules and cannot rotate. However, visualizing cis versus trans molecules by drawing them out and then identifying the dipoles is a way to make this easier.
Sat Nov 21, 2020 10:59 am
Forum: Determining Molecular Shape (VSEPR)
Topic: determining molecular shape
Replies: 10
Views: 77

### Re: determining molecular shape

CO2 is a linear molecule, so the dipoles between the carbon and oxygens cancel out. SO2 is a trigonal planar molecule, so the S=O bonds don't cancel out.
Sat Nov 21, 2020 10:57 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape Names
Replies: 50
Views: 272

### Re: Shape Names

The electron structure is tetrahedral, but the molecular structure is bent. Lone pairs count for the first one but not for the second.
Sat Nov 21, 2020 10:56 am
Forum: Sigma & Pi Bonds
Topic: Difference Between Sigma and Pi Bonds
Replies: 3
Views: 35

### Re: Difference Between Sigma and Pi Bonds

You can think of it as each of the electrons in a pi bond being in different spaces but still make up one bond.
Sat Nov 14, 2020 11:25 am
Forum: Dipole Moments
Topic: Sapling #19
Replies: 12
Views: 72

### Re: Sapling #19

There is an error I think because it should be H2S instead of SO2
Wed Nov 11, 2020 2:35 pm
Forum: Lewis Structures
Topic: Line structures
Replies: 3
Views: 25

### Re: Line structures

Line drawings are extremely simplified forms of depicting molecules. Ends and kinks of a chain are carbons by default unless denoted otherwise, and all hydrogens are omitted unless they are part of branch groups, like -OH.
Wed Nov 11, 2020 2:33 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Textbook Question 2A.21 part D)
Replies: 2
Views: 26

### Re: Textbook Question 2A.21 part D)

Ag+ has no electron in the 5s orbital because filling the 4d orbital is much more favorable.
Wed Nov 11, 2020 2:32 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: F-block?
Replies: 7
Views: 60

### Re: F-block?

A lot of the questions from the book are skipped/omitted in the outline (it even says omit for some complex problems), especially when the f block is involved.
Wed Nov 11, 2020 2:30 pm
Forum: Dipole Moments
Topic: Hydrogen Bonds
Replies: 6
Views: 47

### Re: Hydrogen Bonds

It is a relatively strong force of attraction caused by charges and not a true bond.
Wed Nov 11, 2020 2:28 pm
Forum: Bond Lengths & Energies
Topic: Melting Point
Replies: 3
Views: 21

### Re: Melting Point

I think you are mistaken, as butanol (1-butanol), has a much higher melting point than diethyl ether by about 27 degrees Celsius. This is due to the polarity of the butanol molecule which comes from the -OH group.
Wed Nov 11, 2020 2:10 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: Lecture Question CH4 and CCl4
Replies: 4
Views: 35

### Re: Lecture Question CH4 and CCl4

I'm not sure, I just thought that it was the difference in mass that accounted for this large difference in boiling point
Thu Nov 05, 2020 3:48 pm
Forum: Lewis Structures
Topic: Chemical Formulas
Replies: 8
Views: 55

### Re: Chemical Formulas

Most common polyatomic ions have easily memorizable formulas/structures due to patterns. Naming conventions are used to determine these patterns. For example, in the case of nitrate and nitrite, the -ate suffix refers to the ion with one more oxygen than the -ite suffix. For oxyanions of halogen (pe...
Thu Nov 05, 2020 3:42 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: energy in electron configurations
Replies: 7
Views: 55

### Re: energy in electron configurations

There are two conventions for writing electron configurations, the one where the pattern on the periodic table is visible and the one where the energy level difference is visible. For example, putting 4s before 3d shows the former pattern while putting 3d before 4s shows the latter.
Thu Nov 05, 2020 3:39 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge & Lewis Structures
Replies: 5
Views: 40

### Re: Formal Charge & Lewis Structures

Usually, the one with the correct formal charge allocation is the right answer, but some question may ask for an answer where you list all the allocations and then choose the most likely by basic rules.
Thu Nov 05, 2020 3:36 pm
Forum: Ionic & Covalent Bonds
Topic: configuration
Replies: 4
Views: 15

### Re: configuration

For the D orbital, a rule of thumb is to assume that the group 6 and group 11 elements take an s electron from the closest filled s state to make the d shell full, which is also a state of lower energy than having a $4s^2 3{d^4}$ for example.
Thu Nov 05, 2020 9:44 am
Forum: Ionic & Covalent Bonds
Topic: Sapling Week 5/6 #16
Replies: 2
Views: 23

### Re: Sapling Week 5/6 #16

The key thing to understand here is that a hydrogen bond can only occur between partially positive hydrogen and a partially negative anything else. This means that the hydrogen should be bonded to an electronegative atom (N, O, F) and the other atom should be bonded to a less electronegative atom (C...
Sun Nov 01, 2020 5:37 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Bonds
Replies: 9
Views: 76

### Re: Covalent Bonds

Hydrogen is weakest with covalent and ionic stronger based on the environment they are in. Ionic bonds tend to dissolve in solution, making them extremely weak then, but they are very strong otherwise
Sun Nov 01, 2020 5:35 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron configuration
Replies: 3
Views: 30

### Re: Electron configuration

People sometimes write s first to show the pattern on the p-table and d first to show the energy level
Sun Nov 01, 2020 5:34 pm
Forum: Lewis Structures
Topic: Carbon and triple bonds
Replies: 7
Views: 53

### Re: Carbon and triple bonds

It is because the shape of the orbitals in carbon is tetrahedral, so making a quad bond creates a ton of stress, which makes it impossible for a quad bond to occur
Sun Nov 01, 2020 5:33 pm
Forum: Properties of Light
Topic: spectral lines
Replies: 6
Views: 48

### Re: spectral lines

for emission, n1 is usually the smaller one because that results in a bigger fraction, which makes the whole thing positive
Sun Nov 01, 2020 5:30 pm
Forum: Properties of Light
Topic: How to remember what v is in equations
Replies: 46
Views: 240

### Re: How to remember what v is in equations

Frequency is denoted by nu, which looks like $\nu$, whereas velocity is denoted by the English alphabet 'v'
Sun Nov 01, 2020 5:29 pm
Forum: Administrative Questions and Class Announcements
Replies: 19
Views: 198

Makeup quizzes are on Friday so i expect after then
Fri Oct 23, 2020 12:01 pm
Forum: DeBroglie Equation
Topic: De Broglie Equation v. Speed of Light Equation
Replies: 14
Views: 101

### Re: De Broglie Equation v. Speed of Light Equation

generally, you would use the speed of light equation of electromagnetic traditions, light, and the de Broglie equation for things with mass, such as electrons and basketballs
Wed Oct 21, 2020 2:24 pm
Forum: Administrative Questions and Class Announcements
Topic: Sapling Textbook Glitch
Replies: 2
Views: 36

### Re: Sapling Textbook Glitch

This is due to the typesetting feature they use which can be really inefficient in cases with long page-lengths
Wed Oct 21, 2020 2:15 pm
Forum: Properties of Light
Topic: MHz to Hz 1A.9
Replies: 3
Views: 35

### Re: MHz to Hz 1A.9

The answer you got is correct, 300 MegaHertz frequency is equivalent to 1 meter in wavelength. You can see this because 300 MHz is the same as 3 x 10^8 Hz, which when multiplied by 1 equals the speed of light.
Wed Oct 21, 2020 2:12 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: dx^2-y^2 orbital
Replies: 4
Views: 38

### Re: dx^2-y^2 orbital

I think that its because the orbital is very similar looking to a hyperbolic functions
Tue Oct 20, 2020 3:14 pm
Forum: Properties of Electrons
Topic: Electron model as a circular standing wave
Replies: 2
Views: 27

### Re: Electron model as a circular standing wave

The part that maybe looked like it was out of phase is just a representation that shows that the electron is not statically fixed to an unmoving orbit. The orbit can manipulate in both direction and amplitude (I think) as long as there is a standing wave.
Tue Oct 20, 2020 3:11 pm
Forum: Properties of Electrons
Topic: Geiger and Marsden Experiment
Replies: 2
Views: 27

### Re: Geiger and Marsden Experiment

Basically, the alpha particles, which were known to have mass, were shot into the foil. Then, Geiger and Marsden noted that some of the alpha particles bounced back even though most went through. This lead them to figure out that the foil had both empty spaces in it and it also had a certain place w...
Tue Oct 20, 2020 3:08 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Textbook 1B 25
Replies: 4
Views: 70

### Re: Textbook 1B 25

Correct, you would use the diameter of the atom as $\Delta x$ because that is the boundary of the electron is space.
Mon Oct 19, 2020 11:09 am
Forum: DeBroglie Equation
Topic: Units in Solving Questions regarding De Broglie Equation
Replies: 4
Views: 44

### Re: Units in Solving Questions regarding De Broglie Equation

If you were to use grams, you would get milliJoules instead of Joules and you would have to multiply by $10^3$ to get the right units in joules.
Thu Oct 15, 2020 9:38 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Equation
Replies: 3
Views: 56

### Re: Heisenberg Equation

Use the $\Delta x\Delta p = \frac{1}{4\pi}h$ to find x because you have all the other values already.
Thu Oct 15, 2020 9:36 am
Forum: Properties of Light
Topic: Light Intensity and Photons
Replies: 8
Views: 61

### Re: Light Intensity and Photons

Intensity depends on the number of photons because it is a measure of how many photons are passing through an area at a certain time.
Thu Oct 15, 2020 9:34 am
Forum: Properties of Light
Topic: memorizing electromagnetic spectrum [ENDORSED]
Replies: 3
Views: 53

### Re: memorizing electromagnetic spectrum[ENDORSED]

A good mnemonic to remember them is Roman Men Invented Very Unusual X-Ray Guns, which stands for radio, micro, infrared, visible, UV, x-ray, and gamma rays.
Thu Oct 15, 2020 9:28 am
Forum: Einstein Equation
Topic: m vs nm
Replies: 66
Views: 404

### Re: m vs nm

I don't think it matters which one you use as long as they are the correct conversion. nanometers is a much more readable number so I prefer using nm.
Thu Oct 15, 2020 9:22 am
Forum: Photoelectric Effect
Topic: Frequency vs. Intensity
Replies: 16
Views: 131

### Re: Frequency vs. Intensity

The short way of saying it is that you cant emit electrons if you don't have the right energy (frequency), even if you do have an enormous amount of photons (intensity)
Thu Oct 15, 2020 9:21 am
Forum: Einstein Equation
Topic: e=hv used for particles?
Replies: 9
Views: 225

### Re: e=hv used for particles?

You can only use it for light because the v in E=hv refers to frequency, which most large particles do not show.
Thu Oct 15, 2020 9:15 am
Forum: Quantum Numbers and The H-Atom
Topic: Writing Electron Configurations 1E.23
Replies: 5
Views: 45

### Re: Writing Electron Configurations 1E.23

I am pretty sure you can write them either way. The way with 3d before 4s shows the energy level difference but the opposite shows the structure of the periodic table and where an element lies on it.
Fri Oct 09, 2020 9:39 am
Forum: SI Units, Unit Conversions
Topic: When to convert units?
Replies: 12
Views: 100

### Re: When to convert units?

I usually convert to easily readable or understandable units. For example, I convert nanometers to meters because the number may make more sense in meters, but at other times I might do it the other way around to show an easily understandable measurement in nanometers.
Fri Oct 09, 2020 9:37 am
Forum: Significant Figures
Topic: Which number determines sig figs of the answer?
Replies: 26
Views: 179

### Re: Which number determines sig figs of the answer?

Usually, the number with the least amount of sig figs determines how many sig figs you can use.
Fri Oct 09, 2020 9:35 am
Forum: Empirical & Molecular Formulas
Replies: 5
Views: 48

### Re: Reading Chemical Structure Diagrams

The structure in that problem can be read as though each point between lines that doesn't have a letter associated with it is a carbon atom. Then, depending on the number of bonds each carbon atom has, you add enough hydrogens to each carbon atom to make a total of four bonds.
Tue Oct 06, 2020 3:23 pm
Forum: Limiting Reactant Calculations
Topic: Excess Reactant Help [ENDORSED]
Replies: 3
Views: 50

### Re: Excess Reactant Help[ENDORSED]

To start a problem to find excess reactant, remember that it's all about mole ratios. Let's say you are given the equation: 2\textup{Al} + 3\textup{Cl}_2 \rightarrow \textup{2AlCl}_3 and it says you react 255 g of \textup{Al} with 535 g of \textup{Cl}_2 to get an actual yield of 300 g of product. Fi...
Mon Oct 05, 2020 3:10 pm
Forum: Molarity, Solutions, Dilutions
Topic: Units for Dilution Equation [ENDORSED]
Replies: 23
Views: 208

### Re: Units for Dilution Equation[ENDORSED]

Vanessa Perez wrote:Quick question: is 0.987(10^-4)L the same as 9.87(10^-3)L??

They would be the same if the exponents were reversed:
$9.87\cdot 10^{-4} = 0.000987$
$0.987\cdot 10^{-3} = 0.000987$
Mon Oct 05, 2020 2:24 pm
Forum: Molarity, Solutions, Dilutions
Topic: Units for Dilution Equation [ENDORSED]
Replies: 23
Views: 208

### Re: Units for Dilution Equation[ENDORSED]

I am pretty sure you can you either milliliters or liters as long as you have the same on both sides. When you calculate for one of the variables, you'll always end up with the right units if you do this because either Molar unit or the Volume unit will cancel out.
Sat Oct 03, 2020 4:52 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Kinetic Energy Problem
Replies: 4
Views: 134

### Re: Kinetic Energy Problem

Heisenberg's Uncertainty Equation states that change in momentum and change in position are inversely related with a constant of proportionality of planck's constant divided by 4 pi: \Delta p \cdot \Delta x \geq \frac{h}{4\pi} . In any given example, you should be able to extrapolate the mass of a p...