Search found 72 matches

Thu Jan 14, 2021 9:29 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Weel 1/2 Sapling Question #6
Replies: 3
Views: 19

Re: Weel 1/2 Sapling Question #6

In order to get the desired equation, 2NH3(g)+3I2(g)↽−−⇀N2(g)+6HI(g), you have to add two of the equations that are given. From the four equations given, we can see that adding the first and third one will get us our desired equation. However, realize that the first equation must be multiplied by 3 ...
Thu Jan 14, 2021 9:22 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: pKA and pH
Replies: 8
Views: 44

Re: pKA and pH

pKa & pKb tells you how strong a particular acid/base is, while pH and pOH simply tell you the concentration of OH- and H3O+. However, both are used to describe acids and bases.
Thu Jan 14, 2021 9:19 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pKA, pKB, KA, KB
Replies: 7
Views: 28

Re: pKA, pKB, KA, KB

Yes, the stronger the base, the larger the Kb value and lower the pKb value.
Thu Jan 14, 2021 9:17 pm
Forum: Ideal Gases
Topic: Thermodynamics in Equilibirum
Replies: 6
Views: 31

Re: Thermodynamics in Equilibirum

I would look at outlines 1 & 2 on his website because those are the ones we've done/are doing so far. The bullet points on the outlines tell you all the material you need to know.
Wed Jan 13, 2021 12:54 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: q vs k
Replies: 62
Views: 162

Re: q vs k

Q is the reaction quotient (taken at any time during the reaction). If you let the reaction go until it reaches equilibrium, Q should equal K (since K is the equilibrium constant).
Wed Jan 13, 2021 12:51 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temperature
Replies: 38
Views: 92

Re: Temperature

Yes, as others stated above, you would need to know whether the reaction is endothermic or exothermic (given by delta h).
Wed Jan 06, 2021 1:05 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Small and Large K values
Replies: 3
Views: 23

Re: Small and Large K values

I think that these values are just chosen as they are both clearly very small or large values, so if the value of K was greater/less than that, it would definitely imply that it sits to the left/right.
Wed Jan 06, 2021 1:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When K=1
Replies: 2
Views: 15

Re: When K=1

I think that that is possible looking at it mathematically (for example if the equation is 2R --> P where [R] = 2 mol/L and [P] = 4 mol/L, then K = 2^2/4 = 1). However, I think it is still rare for this to occur, but feel free to correct me if I'm wrong.
Wed Jan 06, 2021 12:53 pm
Forum: Equilibrium Constants & Calculating Concentrations
Replies: 7
Views: 31

If you have two positive values, chances are one of them is larger than the initial concentrations. If x is larger than the initial concentration, then the equilibrium concentration value becomes negative, which is impossible.
Wed Jan 06, 2021 12:50 pm
Forum: Ideal Gases
Topic: Units of Temperature
Replies: 82
Views: 287

Re: Units of Temperature

We use Kelvin.
Wed Jan 06, 2021 12:49 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: change in pressure
Replies: 8
Views: 57

Re: change in pressure

There would be no change as the moles on both side are equal (the reaction is not favored to go to any side).
Tue Dec 15, 2020 5:29 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem community points
Replies: 16
Views: 118

Re: Chem community points

They will be updating the points in a few days (since we were given an extension).
Mon Dec 07, 2020 10:16 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: coordination compounds
Replies: 4
Views: 14

Re: coordination compounds

Yes, as Dr. Lavelle mentioned in the lecture, the most common prefixes are mono-, di-, tri-, tetra-, penta-, hexa-.
Mon Dec 07, 2020 9:59 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Why is HF not classified as a strong acid?
Replies: 19
Views: 117

Re: Why is HF not classified as a strong acid?

HF is not a strong acid as F is so electronegative, which means that HF does not easily dissociate into H+ and F- easily in water. This is why, as atomic radius increases, the acids become stronger as they are able to dissociate much easier.
Mon Dec 07, 2020 9:56 am
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids and Bronsted Bases
Replies: 4
Views: 15

Re: Bronsted Acids and Bronsted Bases

Bronsted Acids are proton donors (donate H+) while Bronsted Bases are proton acceptors (accept H+). Typically, Bronsted Acids have hydrogen (for example: HCl) which dissociates into H+ ions in water to form H3O+.
Mon Dec 07, 2020 9:53 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Sapling Question 9 (Week 10)
Replies: 5
Views: 30

Re: Sapling Question 9 (Week 10)

You would first find the pOH = -log[OH-]. Then, using the value for pOH, you can find the pH by doing 14-pOH = pH. Once you've converted all of your values to pH, you can see which is more acidic and which is more basic (acids have pH < 7, bases have pH > 7).
Mon Dec 07, 2020 9:50 am
Forum: Amphoteric Compounds
Topic: Amphoteric Compound Acid/Base Character
Replies: 4
Views: 13

Re: Amphoteric Compound Acid/Base Character

I think that an amphoteric compound tends to be a weak acid/base as it can be either acid or base. I would imagine that it would be difficult for a strong acid to behave as a base and vice versa.
Mon Dec 07, 2020 9:47 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Negative pH of acid
Replies: 16
Views: 68

Re: Negative pH of acid

I think that the pH scale goes from 0-14 (as it is found by finding -log[H+]). In order for the pH to be negative, the concentration of H+ would have to be greater than 1M.
Sun Dec 06, 2020 11:20 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH vs pOH
Replies: 9
Views: 63

Re: pH vs pOH

Yes, the pOH scale also goes from 1-14, where 7 is neutral. Also, pOH + pH = 14.
Thu Dec 03, 2020 10:08 pm
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Inorganic and Organic
Replies: 7
Views: 67

Re: Inorganic and Organic

Organic compounds (or at least most of them) contain C-H bonds (an example is C6H12O6 which is glucose). Inorganic compounds do not have C-H bonds.
Thu Dec 03, 2020 10:03 pm
Forum: Hybridization
Topic: pcl3
Replies: 8
Views: 48

Re: pcl3

There are four regions of electron density (three single bonds and one lone pair). Thus, the hybridized orbital that corresponds to four regions of electron density is sp3 (as there are four orbitals, one for each region of electron density).
Thu Dec 03, 2020 9:59 pm
Forum: Naming
Topic: Sapling 9 #1
Replies: 7
Views: 39

Re: Sapling 9 #1

I agree with the answer given above. The Cl2 that is outside of the brackets is not a part of the coordination sphere, so you would write it separately instead of grouping it with the chlorine inside the brackets. Thus, instead of it being trichloro, it would be simply chloro to represent the chlori...
Thu Dec 03, 2020 9:56 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids and Bases
Replies: 7
Views: 30

Re: Bronsted Acids and Bases

A Bronsted Acid is a proton donor while a Bronsted Base is a proton acceptor. It is just another way to define/distinguish between acids and bases (another way acids and bases are described is Lewis Acid (electron pair acceptor) and Lewis Base (electron pair donor).
Thu Dec 03, 2020 9:51 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: pH Chart
Replies: 16
Views: 111

Re: pH Chart

I think we would need to memorize it. However, it is pretty simple to remember (<7 is an acid, >7 is a base, 7 is neutral).
Thu Nov 26, 2020 8:26 pm
Forum: Hybridization
Topic: Sp3d or dsp3
Replies: 22
Views: 862

Re: Sp3d or dsp3

It can be written either way, they both work and represent the same thing.
Thu Nov 26, 2020 8:24 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Coordination Compounds
Replies: 5
Views: 31

Re: Coordination Compounds

Yes, I agree with the other answers given. OH2 and H2O are the same compound, however, it was written as OH2 to show the bonding order.
Thu Nov 26, 2020 8:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Chart
Replies: 18
Views: 104

Re: VSEPR Chart

Yes, I think that we're expected to have the molecular shapes & bond angles memorized. However, there are many great infographics & charts online that concisely explain everything and I think Dr. Lavelle also does a really good job going in depth in his lectures.
Thu Nov 26, 2020 8:20 pm
Forum: Hybridization
Topic: Lecture 23 Question
Replies: 2
Views: 24

Re: Lecture 23 Question

Yes, I think that might have been an error since I also think that ethene has two sp2 hybridization orbitals.
Thu Nov 26, 2020 8:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pair Volume
Replies: 4
Views: 17

Re: Lone Pair Volume

With lone pairs, they are more delocalized than bonding electrons. As a result, lone pairs have greater electron-electron repulsion compared to bonding electrons, so they would want to be farther away.
Thu Nov 26, 2020 8:16 pm
Forum: Hybridization
Topic: Single Bonds and Sigma Bonds
Replies: 23
Views: 111

Re: Single Bonds and Sigma Bonds

Yes, all single bonds are sigma bonds while double bonds have 1 sigma and 1 pi bond and triple bonds have 1 sigma and 2 pi bonds.
Sun Nov 22, 2020 5:41 pm
Forum: Hybridization
Topic: Pi and Sigma Bonds
Replies: 10
Views: 81

Re: Pi and Sigma Bonds

Yes, I agree with the others. Sigma and pi bonds occur with all covalent bonds. However, single bonds only have a sigma bond while double & triple bonds have sigma & pi bonds.
Thu Nov 19, 2020 4:55 pm
Forum: Dipole Moments
Topic: Dipole Moments and Electronegativity
Replies: 2
Views: 13

Re: Dipole Moments and Electronegativity

Technically electronegativity is quantifiable (each element has a specific electronegativity number) so if those numbers were given to you, you would be able to find the exact difference. However, for now, we just need to know the trend that electronegativity follows and we don't need to do exact ca...
Thu Nov 19, 2020 4:52 pm
Forum: Electronegativity
Topic: Most Electronegative Element
Replies: 5
Views: 53

Re: Most Electronegative Element

Helium is a noble gas, so it does not want more electrons as its valence shell is already full. Fluorine, on the other hand, is a halogen, and only needs one more electron to form an octet. Thus, it has the higher electronegativity.
Thu Nov 19, 2020 4:48 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 [ENDORSED]
Replies: 19
Views: 127

Re: London Forces[ENDORSED]

Yes, LDF are found in all molecules and they are the weakest of all the intermolecular forces.
Thu Nov 19, 2020 4:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape Names
Replies: 50
Views: 299

Re: Shape Names

Yes, it is called bent as there are two lone pairs of electrons and two pairs of bonded electrons.
Thu Nov 19, 2020 4:41 pm
Forum: Dipole Moments
Topic: Midterm 2 Results
Replies: 7
Views: 112

Re: Midterm 2 Results

I think that we can expect it to take around the same time as last time (I'm guessing we'll get our scores sometime next week, after everyone has taken the midterm this week).
Sun Nov 15, 2020 6:48 pm
Forum: Ionic & Covalent Bonds
Topic: Textbook 2A.23
Replies: 1
Views: 10

Re: Textbook 2A.23

So for all of these questions, you would have to use the expected charges. For a, we know that magnesium has a +2 charge in order to be stable and arsenic has a -3 charge to be stable. To form the chemical formula, you would use the charges to decide how many of each ion is needed to make a stable c...
Thu Nov 12, 2020 12:39 pm
Forum: Ionic & Covalent Bonds
Topic: textbook 2C.1
Replies: 4
Views: 22

Re: textbook 2C.1

Some species have an odd number of valence electrons, and therefore cannot form a full octet, and may have an unpaired electron (known as a radical). For this problem, I would draw each Lewis structure to see which structures have an unpaired electron.
Thu Nov 12, 2020 12:32 pm
Forum: Lewis Structures
Replies: 12
Views: 38

Radicals have one unpaired electron (for example, in NO). Radicals form when species have an odd number of valence electrons (for example, N has 5 valence electrons).
Thu Nov 12, 2020 12:25 pm
Forum: Lewis Structures
Topic: Textbook Problem 2B.9
Replies: 1
Views: 33

Re: Textbook Problem 2B.9

For this problem, I first determined the number/moles of each atom/molecule. So for example, for part a, which is ammonium chloride, you know that ammonium is NH4 and chloride (chlorine) is just Cl. In order for both of them to be stable, NH4 needs to get rid of one electron and Cl needs to gain an ...
Thu Nov 12, 2020 12:18 pm
Forum: Dipole Moments
Topic: Liquid vs. Solid vs. Gas
Replies: 5
Views: 33

Re: Liquid vs. Solid vs. Gas

In the lecture, it was mentioned that high polarizability means higher attractive force. The greater the number of electrons, the more polarizable it is. When there is high polarizability, and therefore more attraction, instead of it being a liquid, it would form a more waxy solid (as seen in the le...
Wed Nov 11, 2020 6:54 pm
Forum: Dipole Moments
Topic: Sapling #17
Replies: 7
Views: 62

Re: Sapling #17

London dispersion forces occur between all molecules and are also known as Van der Waals forces and induced dipole-induced dipole forces in the lecture. In this question, you would look at only nonpolar molecules as they would only exhibit London dispersion forces (others would exhibit London disper...
Sun Nov 08, 2020 8:16 pm
Forum: Coordinate Covalent Bonds
Topic: Just to clear it up
Replies: 13
Views: 239

Re: Just to clear it up

Yes this is true as the Lewis base is the one donating electrons while the Lewis acid gains the electrons.
Wed Nov 04, 2020 11:05 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Representing Electron Configurations for P-orbitals
Replies: 6
Views: 38

Re: Representing Electron Configurations for P-orbitals

Yes, I believe that is correct. You would have one electron in each of the px, py, and pz orbitals to have the lowest energy.
Wed Nov 04, 2020 2:50 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge and Stability
Replies: 7
Views: 20

Re: Formal Charge and Stability

A stable structure is one that has a formal charge of 0. This is because it would have the lowest energy.
Tue Nov 03, 2020 1:23 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge and Lewis Structures
Replies: 10
Views: 71

Re: Formal Charge and Lewis Structures

I think that finding the formal charge is a good way to check that your Lewis structure is the most stable. I agree, I think that it is mostly used for structures with resonance as they have multiple Lewis structures for the molecule.
Tue Nov 03, 2020 12:26 pm
Forum: Resonance Structures
Topic: Resonance and double bonds
Replies: 4
Views: 29

Re: Resonance and double bonds

This is also a double bond related question. How do we exactly know when there has to be a double bond when creating the Lewis Structure? We know what bonds to use based on the amount of available valence electrons and the octet rule. For example, in NO3-, if you try to use only single bonds, you w...
Mon Nov 02, 2020 10:56 pm
Forum: Lewis Structures
Topic: charge by square bracket
Replies: 8
Views: 61

Re: charge by square bracket

Yes, the charge represents the charge of the polyatomic ion/molecule. NO3 has a -1 charge, hence the -1 sign at the top right. This is because the Lewis structure drawing itself cannot showcase the specific charge of the molecule, so it is shown in this way.
Mon Nov 02, 2020 10:54 pm
Forum: Lewis Structures
Topic: sides
Replies: 12
Views: 129

Re: sides

Yes I agree, it can be on any side. What matters is that the number of electrons add up to the available valence electrons and that the appropriate bonds are used (single, double, triple).
Sun Nov 01, 2020 7:45 pm
Forum: Ionic & Covalent Bonds
Topic: Different Bonds
Replies: 8
Views: 42

Re: Different Bonds

Ionic bonds form between a metal and a nonmetal atom (an example from the lecture: KCl, potassium chloride). In an ionic bond, the electron transfer results in an an octet of electrons for each atom. The cations lose electrons and the anions gain electrons. In covalent bonds, however, cations cannot...
Fri Oct 30, 2020 8:59 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: h vs. ħ?
Replies: 11
Views: 120

Re: h vs. ħ?

h-bar is h/2pi. You can use either equation, but personally, I prefer just remembering h and using ∆p ∆x ≥ h/4π.
Fri Oct 30, 2020 8:56 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Units for Uncertainty in Position
Replies: 6
Views: 53

Re: Units for Uncertainty in Position

The uncertainty in position refers to the position of the electron (which is in meters), so it would also be in meters.
Thu Oct 29, 2020 4:26 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: En and E
Replies: 3
Views: 42

Re: En and E

En refers to the energy at an energy level, n. The E in E=hv refers to the energy of the incoming photon, while Ek in Ek = 1/2 mv^2 refers to the energy of the electron.
Thu Oct 29, 2020 4:22 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: l=4
Replies: 13
Views: 85

Re: l=4

l could be 4, but I think that in this class, we'll only deal with elements up to l=3.
Thu Oct 29, 2020 4:20 pm
Forum: DeBroglie Equation
Topic: p
Replies: 19
Views: 159

Re: p

p represents momentum, which can be found by multiplying mass and velocity.
Wed Oct 21, 2020 9:03 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Problem 1D.13
Replies: 4
Views: 24

Re: Problem 1D.13

For this question, l refers to the orbital angular momentum, which is found by finding n-1. However, the l values that are possible are everything from 0 up to n-1. Therefore, when n=7, the possible values can be 0, 1, 2, 3, 4, 5, 6 which are 7 total values.
Wed Oct 21, 2020 8:58 pm
Forum: *Shrodinger Equation
Topic: Schrodinger's Equation
Replies: 3
Views: 33

Re: Schrodinger's Equation

We haven't learned how to utilize it mathematically yet, however, conceptually, it essentially describes the concept that an electron (which has wavelike properties and indeterminacy in momentum) can be described by a wave function.
Wed Oct 21, 2020 6:10 pm
Forum: *Shrodinger Equation
Topic: Electron Density
Replies: 5
Views: 35

Re: Electron Density

Electron density refers to the amount of electrons in a specific area (also known as the probability of finding an electron in that area). If there are a lot of electrons in one area, then the probability of finding an electron is high. In s-orbitals, where there are no nodal planes, the electron de...
Wed Oct 21, 2020 6:05 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Electron Example from Lecture 9
Replies: 4
Views: 50

Re: Electron Example from Lecture 9

Yes, technically, nothing can travel faster than the speed of light, and in the example from class, the velocity comes out to be much higher than the speed of light.
Wed Oct 21, 2020 6:02 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg Indeterminacy Question
Replies: 2
Views: 21

Re: Heisenberg Indeterminacy Question

Yes, I agree, I think that it was just added as a funny last question in the module.
Fri Oct 16, 2020 12:43 pm
Forum: Einstein Equation
Topic: Textbook Question 1A.3
Replies: 3
Views: 60

Re: Textbook Question 1A.3

As frequency and wavelength are inversely proportional, as frequency decreases, wavelength increases. The extent of change refers to the slope of the wave. When the wavelength increases, the slope, or the extent of change, decreases.
Fri Oct 16, 2020 12:39 pm
Forum: Einstein Equation
Topic: Equation Sheet
Replies: 15
Views: 132

Re: Equation Sheet

I think that an equation sheet with constants is provided.
Wed Oct 14, 2020 11:32 pm
Forum: Einstein Equation
Topic: Exercise 1A.9
Replies: 2
Views: 43

Re: Exercise 1A.9

I also got 1m. I think that the answer at the back of the book just has the wrong units.
Tue Oct 13, 2020 11:02 pm
Forum: Properties of Electrons
Topic: Textbook 1A.15
Replies: 3
Views: 43

Re: Textbook 1A.15

Hi! The equation for finding the n level is E = -hR/n^2. In this problem, we have n(initial) and n(final), meaning we would need to find E(initial) and E(final) in order to solve for the corresponding values of n. First, you would have to find delta E (total Energy), which is found by the equation E...
Tue Oct 13, 2020 10:51 pm
Forum: Properties of Light
Topic: Photoelectric spectrum
Replies: 24
Views: 163

Re: Photoelectric spectrum

Yes, I agree, I don't think we have to memorize the entire spectrum but knowing the general order (which rays have a higher wavelength, what color corresponds to a lower wavelength, etc.) would definitely help while doing problems.
Mon Oct 12, 2020 11:58 am
Forum: Photoelectric Effect
Topic: Where does photon energy go if it does not emit an electron?
Replies: 6
Views: 69

Re: Where does photon energy go if it does not emit an electron?

The electrons will still absorb the energy, but it would not be enough for them to be ejected/excited to a higher energy level.
Fri Oct 09, 2020 11:16 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Stochiometric Coefficients
Replies: 6
Views: 62

Re: Stochiometric Coefficients

Stoichiometric coefficients are just used to highlight the ratios of each reactant and product in a chemical equation. They are not measured in moles or any units.
Thu Oct 08, 2020 10:54 pm
Forum: Photoelectric Effect
Topic: Module: Atomic Spectra
Replies: 1
Views: 45

Re: Module: Atomic Spectra

In the problem, it states that 1 meter = 1,650,763.73 wavelengths. That means that in order to find the length of each wavelength, you would need to divide 1 meter by 1,650,763.73 wavelengths = 6.058 x 10 ^-7 meters. Then, using E = hc/lamda, you would plug in Planck's constant for h, the speed of l...
Wed Oct 07, 2020 3:00 pm
Forum: Balancing Chemical Reactions
Topic: Combustion Products
Replies: 13
Views: 69

Re: Combustion Products

I agree with the others, the mole ratio of CO2 and H2O in the products would vary based on the reaction. You would have to balance the chemical equation just as you would for any other reaction.
Wed Oct 07, 2020 2:58 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactants
Replies: 9
Views: 55

Re: Limiting Reactants

To answer both questions, I think that it is pretty unlikely (based on the lectures & problems in the textbook) that there would be more than one limiting reactant (since the only one that is going to limit how much product is produced is the first one that gets "used up.") However, if...
Mon Oct 05, 2020 12:54 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Fundamentals Section M Exercise M.11
Replies: 4
Views: 42

Re: Limiting Reactant Fundamentals Section M Exercise M.11

I think that the colon is just there to highlight what the product of the equation is (in the first equation, P4O6 is created). It's not a part of the equation and I do not think it has any other significance other than that!
Mon Oct 05, 2020 12:50 pm
Forum: Balancing Chemical Reactions
Topic: Stoichemetric Coeffiecients
Replies: 12
Views: 141

Re: Stoichemetric Coeffiecients

In the lecture, it was mentioned that stoichiometric coefficients must be in the lowest whole number possible, so I assume it is necessary. Hope this helps!