CHEMISTRY COMMUNITY

Andre Fabian 1F

BOOST!! Big thank you to Ayesha for this idea!! This is really wholesome, and I hope the entire teaching team enjoys it!!

Andre Fabian 1F

Laura 3l wrote:There were so many great performances!

Thank you Laura!! This event wouldn't be possible without the support from everyone here!!

Andre Fabian 1F

Yeah, you're right in saying that neither is favored, but it would be more accurate to say that neither is favored significantly, I think. K=1 would be where the reactions are occurring at the exact same rate, but anything between 10^-3 and 10^3 is not significant enough to favor a particular direc...

Andre Fabian 1F

This event was really cool, especially that it was planned out by fellow classmates and supported by our professor and TAs. Hopefully, this becomes an annual tradition for Lavelle's 14 series courses, I'm sure future students would find as much fun as we did. That would be amazing!! I'm super glad ...

Andre Fabian 1F

Hey everybody! We would like to thank our amazing hosts, judges, special guests, contestants, and audience members for a wonderful event. We couldn't have done this without you, and for that we're extremely thankful. And now, for our WINNERS! 1st In first place, we have CHARLIE RUSSELL singing My Fu...

Andre Fabian 1F

[CHEM 14B KARAOKE] Hello everyone! Adila and I, along with several amazing people from the Chemistry 14B GroupMe, are presenting Karaoke Night w/ DJ Lavelle! When: Saturday, March 6th @ 2pm-4pm (tentative time) Where: Discord https://discord.gg/6BQxQTXJcQ Sign-Up Here: https://forms.gle/Qmw1D6F95EP...

Andre Fabian 1F

A galvanic (voltaic) cell consists of an electrode composed of aluminum in a 1.0 M aluminum ion solution and another electrode composed of gold in a 1.0 M gold(III) ion solution, connected by a salt bridge. Calculate the standard potential for this cell at 25 °C. Hi can someone explain the process ...

Andre Fabian 1F

Hi, can someone explain how you know when a reaction is spontaneous or nonspontaneous as written using the standard reduction potentials? Thank you If the standard cell potential of a reaction (Eo,cell = Eo,red(cathode) - Eo,red(anode)) is greater than 0, the reaction is spontaneous as written, and...

Andre Fabian 1F

Calculate the cell potential for the reaction as written at 25.00 °C , given that [Zn2+]=0.801 M and [Fe2+]=0.0180 M . Use the standard reduction potentials in this table. Zn(s)+Fe2+(aq)↽−−⇀ Zn2+(aq)+Fe(s) How do you obtain the Eo to use in the Nernst equation? Thank you! You have to use a table of...

Andre Fabian 1F

Calculate the cell potential for the reaction as written at 25.00 °C , given that [Zn2+]=0.790 M and [Ni2+]=0.0110 M . Use the standard reduction potentials in this table. Zn(s)+Ni2+(aq)↽−−⇀ Zn2+(aq)+Ni(s) Can someone explain how to start this question? In this question we'd be using the Nernst equ...

Andre Fabian 1F

Hi! I've been stuck on #18 for a while, and I can't figure out what I'm doing wrong. May someone please point out my mistake and show me how to do this correctly? Thank you! One of the most recognizable corrosion reactions is the rusting of iron. Rust is caused by iron reacting with oxygen gas in t...

Andre Fabian 1F

UPDATE: We may be getting a special guest!

Andre Fabian 1F

[CHEM 14B KARAOKE] Hello everyone! Adila and I, along with several amazing people from the Chemistry 14B GroupMe, are presenting Karaoke Night w/ DJ Lavelle! When: Saturday, March 6th @ 2pm-4pm CONFIRMED TIME Where: Discord https://discord.gg/6BQxQTXJcQ Sign-Up Here: https://forms.gle/Qmw1D6F95EPiTX...

Andre Fabian 1F

Can someone please explain the part where Lavelle said that we should use platinum as an electrode to transfer electrons? Why do we need this? Because platinum is a relatively stable metal, it can transfer electrons between the two species in the cathode and anode without getting oxidized itself (r...

Andre Fabian 1F

Hi! I was wondering what exactly was the purpose of the salt bridge that Dr. Lavelle mentioned in the electrode experiment? How does it help conduct the flow of electrons? Thanks! According to Dr. Lavelle's (2/17) lecture, salt bridges or porous disks are used to allow ion transfer while keeping th...

Andre Fabian 1F

What is the difference between Pt(100), Pt(110) and Pt(111)? In an electrochemical cell utilizing a platinum (Pt) anode, what is the difference and what kind of implications would be expected from using either Pt(100), Pt(110) or Pt(111)? To summarize some of the posts from the linked thread, densi...

Andre Fabian 1F

in lecture 18, dr lavelle referred to cells as electrodes and half rxns. do these terms all mean the same thing? like an electrode is the molecule being reduced or oxidized? No, these terms do not necessarily refer to the same thing. They are all part of electrochemistry, which is the study of elec...

Andre Fabian 1F

A constant-volume calorimeter was calibrated by carrying out a reaction known to release 3.50 kJ of heat in 0.200 L of solution in the calorimeter (q=−3.50kJ), resulting in a temperature rise of 7.32°C. In a subsequent experiment, 100.0 mL of 0.200 M HBr(aq) and 100.0 mL of 0.200M KOH(aq)were mixed...

Andre Fabian 1F

Hello! Question: For a gaseous reaction, standard conditions are 298 K and a partial pressure of 1 bar for all species. For the reaction N2(g)+3H2(g)↽−−⇀2NH3(g) the standard change in Gibbs free energy is ΔG∘=−72.6 kJ/mol. What is ΔG for this reaction at 298 K when the partial pressures are PN2=0.2...

Andre Fabian 1F

"Calculate the heat that must be supplied to a copper kettle of mass 500.0g containing 400.0g of water to raise its temperature from 22.0 C to the boiling point of water, 100.0 C." How come the solutions manual gives the heat change necessary to raise both the temperature of the copper AN...

Andre Fabian 1F

A particular container holds 4.89 mol of neon gas. The volume of this container can be altered by sliding a piston in or out. The volume is changed from 7.60 L to 11.90 L while at the same time the temperature is changed from 279 K to 362 K. The molar heat capacity, CV,m, for neon is 12.47 J/(mol ·...

Andre Fabian 1F

Hi everyone! I was wondering if you guys could explain to me the concept of molar entropy, and how we would determine whether something has a higher molar entropy than another thing? 4H.1: Which substance in each of the following pairs has the higher molar entropy at 298 K: (a) HBr(g) or HF(g); (b)...

Andre Fabian 1F

I understand the equation you have to use and I've been following it and multiplying the appropriate coefficients to the standard molar entropies for the products and reactants but I'm still not getting the right answer. Could someone with similar numbers walk me through how you solved this? Also, ...

Andre Fabian 1F

JTieu_1L wrote:What is the point of calculating residual entropy?

Residual entropy is calculated because it's nearly impossible to have zero entropy within a real-life substance. For example, a CO molecule can be positioned as C-O or O-C. Lavelle talks about it a little bit in today's lecture.

Hope this helps!

Andre Fabian 1F

Hey!

For this problem you'd use the following equation:
mc(deltaT) + deltaHfus(m) = mc(deltaT)

heat required to change the temperature of the ice + the heat required to melt the ice = heat released from cooling water

Hope this helps!

Andre Fabian 1F

isn't the equation already balanced though? What kind of stoichiometry do you mean? Sorry I am just kind of confused how I can convert it from solid to gas in this equation Hey! You'd use the grams given to you to calculate the number of moles. With that value, you can calculate volume through PV=n...

Andre Fabian 1F

Hey!

For this problem you'd use the following equation:
mc(deltaT) + deltaHfus(m) = mc(deltaT)

heat required to change the temperature of the ice + the heat required to melt the ice = heat released from cooling water

Hope this helps!

Andre Fabian 1F

To solve for path A, you should use the equation w = -nRTln(Vf/Vi) You can rearrange the PV=nRT equation to calculate the number of moles and then plug in the given values into the -nRTln(Vf-Vi) equation. For path B you need to use the w = -P*deltaV and you are given the pressure and volume values....

Andre Fabian 1F

Hey! Someone posted this question earlier.

For this problem you'd use the following equation:
mc(deltaT) + deltaHfus(m) = mc(deltaT)

heat required to change the temperature of the ice + the heat required to melt the ice = heat released from cooling water

Hope this helps!

Andre Fabian 1F

Hi! I'm having a little bit of trouble with this problem: An ice cube with a mass of 47.2 g at 0.0 C is added to a glass containing 407 g of water at 45.0 C. Determine the final temperature of the system at equilibrium. The specific heat capacity of water, Cs, is 4.184 J/g⋅C, and the standard entha...

Andre Fabian 1F

I'm having trouble with this question: A sample of an ideal gas in a cylinder of volume 3.25 L at 298 K and 2.16 atm expands to 7.43 L by two different pathways. Path A is an isothermal, reversible expansion. Path B has two steps. In the first step, the gas is cooled at constant volume to 1.01 atm ...

Andre Fabian 1F

Can somebody help me clarify how pressure works depending on the type of system (open, closed, isolated)? If a system is open, it can exchange matter and energy with its surroundings (i.e. a beaker of water evaporating and lacking insulation). If a system is closed, it can exchange energy with its ...

Andre Fabian 1F

Does anyone understand why we need to specify if we are measuring molar heat capacity under constant volume or constant pressure? I rewatched that portion of monday's lecture like 5 times but I still can't grasp what Dr. Lavelle is trying to say. Please and thanks! We need to differentiate between ...

Andre Fabian 1F

A 0.773 mol sample of NO2(g), initially at 298 K and 1.00 atm, is held at constant pressure while enough heat is applied to raise the temperature of the gas by 12.7 K. Calculate the amount of heat Q required to bring about this temperature change, and find the corresponding total change in the inte...

Andre Fabian 1F

Hello! I may have missed this concept in lecture, but I was solving Sapling Week 3/4 Q. 12, and it used the equation q = C(deltaT) instead of q=mC(deltaT) to determine the heat capacity of the calorimeter, so I was wondering in what situations we would use the first equation and in what situations ...

Andre Fabian 1F

I was looking at the bullet points of topics listed in Outline 1 and one bullet point said "use equilibrium constants to predict solubility." I can't find anything about this topic in my notes. Did we ever learn this? If so, how do we use equilibrium constants to predict solubility? Hi! I...

Andre Fabian 1F

Hi! What should we know about Carbon in the graphite form? According to Lavelle's lecture, he mentioned that graphite is the most stable form of Carbon found in nature. He used this in an example of calculating standard reaction enthalpies, where solid graphite reacts with hydrogen and oxygen gas t...

Andre Fabian 1F

In this textbook problem, it says although (PO2)3/(PO3)2 is the same, (PO2)/(PO3) will be different. Why is this the case? I thought that they would both be the same. Thanks! Mathematically, they are different because one has the partial pressures raised to different exponents, while the other does...

Andre Fabian 1F

The question is: Estimate the concentrations of (a) H3O1 and (b) OH2 at 25 8C in 6.0 3 1025 m HI(aq). My question is how will I know how HI molar ratio to H3O? I know HI is a strong acid so it will dissociate almost completely. Because HI is a strong acid, you can assume that the acid is completely...

Andre Fabian 1F

In textbook problem 5G-3, the H2O concentration is included in K. Is this because H2O is in its gas state? Thanks! Yes! Unless the species is a pure solid or liquid, or a solvent whose concentration barely changes within the reaction (i.e. water), then it is always contained in the K equation. Hope...

Andre Fabian 1F

why do we have to check whether K is less than 10^-4 in order to approximate? what does that mean? and if that condition is not met, what happens? If K is less than 10^-4, we can omit it from the K equation. This is because if you would subtract such a small value from a much larger value, the diff...

Andre Fabian 1F

Hi everyone! I had trouble with the problem that had multiple given equations to solve for K. I was able to solve the problem, but it took me a lot of tries and a lot of time. Can someone explain how they worked through the problem with the steps and what worked best for you in terms of how you sol...

Andre Fabian 1F

HClO is a weak acid ( Ka=4.0×10−8 ) and so the salt NaClO acts as a weak base. What is the pH of a solution that is 0.040 M in NaClO at 25 °C? First, you have to get the Kb value of ClO- (Na is a spectator ion) by doing 10^-14/Ka Then, create an ICE table using the provided moles of NaClO and setti...

Andre Fabian 1F

At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.200 M and [NO]=0.600 M. N2(g)+O2(g)↽−−⇀2NO(g) If more NO is added, bringing its concentration to 0.900 M, what will the final concentration of NO be after equilibrium is re‑established? I keep getting 0.75 my K is 9 and ...

Andre Fabian 1F

From my notes it didn't seem like he was necessarily adding the two values, but instead demonstrating how extrapolation of the Hydronium ion concentration could lead to miscalculations. In the end he told wrote that if [H3O+] < 10^-7, then the solution would be considered neutral because we know tha...

Andre Fabian 1F

Yeah! So whenever there's a coefficient in an equation, it would correspond to a power in the K equation!

Andre Fabian 1F

It's exactly as the person above said! If you're given partial pressures, you would substitute them into an ICE box, plugging in what you know for the Initial, using the given chemical reaction coefficients to write out the change, then using those values to write the equilibrium partial pressures. ...

Andre Fabian 1F

Hi guys can someone please help guide me through this problem because I cannot seem to get the correct answer, thanks! At a certain temperature, the given reaction has an equilibrium constant of Kp=425. PCl3(g)+Cl2(g)↽−−⇀PCl5(g) PCl5 is placed in a sealed container at an initial pressure of 0.0290 ...

Andre Fabian 1F

For the Sapling question where they had us determine the equilibrium constant given two or more of the given equations, why would the equilibrium constant of the hydrogen iodide reaction be cubed before finding the product of the two equilibrium constants? It would be cubed because the reaction for...

Andre Fabian 1F

Hello, I've been having trouble trying to work this problem. I don't know if I'm doing it right but I multiplied the given equilibrium moles of O2 by 2 to get 0.240 mol for SO2. I then added the equilibrium moles of SO2 and O2 to get 0.360, which I then subtracted from the 0.820 initial moles of SO...

Andre Fabian 1F

At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.100 M and [NO]=0.600 M. N2(g)+O2(g)↽−−⇀2NO(g) If more NO is added, bringing its concentration to 0.900 M, what will the final concentration of NO be after equilibrium is re‑established? Hi. I know there's already a post ...

Andre Fabian 1F

What is the relationship between pH and pKa, and how does this factor into negative charges/neutral compounds? pH and pKa are similar in as both values decrease, the acid is stronger. I'm not sure what you mean by your second question, but these are the formulas to calculate each: pKa = -log(Ka) pH...

Andre Fabian 1F

Hi everyone, How can you tell that a substance is amphoteric? For instance, referring to the Sapling Week 10 HW Question 2: How are you able to tell that H2PO4- can act as a Bronsted acid and a Bronsted base? An amphoteric substance is one able to act as both an acid and a base. In this case, a sub...

Andre Fabian 1F

So electron diffraction is a phenomenon observed when a beam of electrons passes through a very small opening, and as a result of constructive/destructive interference (a property of waves only), a pattern of electron density is generated that shows high/low presence in unexpected places. ie, becau...

Andre Fabian 1F

I realize from the photoelectric effect that the electrons are emitted when each photons have enough energy to meet the threshhold. And I thought professor said that if each photon energy does not meet the quota, then they just go through the atom. Then, how do electrons get excited? Excited electr...

Andre Fabian 1F

Adding on to Hannah, elements in period 3 and beyond all have the ability to hold an expanded octet given their d orbitals electrons.

Hope this helps!

Andre Fabian 1F

To add on to what Alice said, HClO3 can also be considered a strong acid, but not in every situation. For the strong bases, it's pretty much a "b" shape on the left side of the period table (LiOH, NaOH, KOH, RbOH, CsOH, CaOH, SrOH, BaOH) Why does Mg(OH)2 not fall into the strong base cate...

Andre Fabian 1F

Resonance structures are ones with delocalized electrons, meaning electrons flow freely throughout the system. Because of this, the actual bond length is equal throughout the system, calling for a more stable overall structure.

Hope this helps!
Andre

Andre Fabian 1F

In Dr. Lavelle's lectures he stated that H+ and H3O+ for the purposes in this class can be used interchangeably, but he mentioned that in later chemistry classes, in chemical equations we should write it out as HA + H20 = A +H30. In addition, pH can be calculated as pH = -log10[H+] Hope this helps! ...

Andre Fabian 1F

Strong acids are characterized by their ability to dissociate completely into H+ ions. HF has an extremely short bond because of its small atomic radius (thus the nucleus of Fluorine has a greater pulling power), as well as it's high electronegativity. Because of HF's properties, HF is unable to com...

Andre Fabian 1F

Because of a higher electronegativity, Chlorine can pull electrons away from other atoms, delocalizing them. And as such, it's a more stable acid because that molecule has resonance structures.

Hope this helps!
Andre

Andre Fabian 1F

Hi there! Another way of thinking of it is how ionic bonds aren't really 'bonds.' The ions are attached together in a lattice connected by their charges, with electrons flowing throughout them. As such, it can be said that bonds with a higher difference in electronegativity can be classified as weak...

Andre Fabian 1F

Hi there! We can determine relative melting and boiling points by looking at bond strength within a molecule. For example, a molecule with a single bond is much weaker than the same molecule harboring a double bond. As such, (given that as the bond order increases, the length of the bond decreases, ...

Andre Fabian 1F

Hi there! To determine the relative ionic character of an atom, we could do one of two things: generalize based on their positions on the periodic table, or subtract the electronegativities of the constituent atoms in the compounds. Using the former justification, we can identify that Bromine is hig...

Andre Fabian 1F

I agree with what everyone has stated beforehand. Adding on, electronegativity tends to increasing going up a group or across (left to right) in a period. As such, we could infer that the more "negative" pole of a molecule tends to center around atoms found in the upper right corner of the...

Andre Fabian 1F

Hi there! Octet exceptions occur for elements that contain d-block electrons (i.e. in and past the third period on the periodic table). My interpretation of "accommodating" would mean when would we use this rule? Normally, we would use the expanded octet in order to ensure the stability of...

Andre Fabian 1F

Nevermind, I just missed a question at the bottom, my bad.

Andre Fabian 1F

Dr. Lavelle mentioned in one of his lectures that that 4s 3d rule only applies on element 20 and before; after that it's 3d 4s as per usual.

Hope this helps!

Andre Fabian 1F

Polar molecules contain polar bonds which contribute to the formation of dipoles. A good rule of thumb to keep in mind is that if a molecule has a symmetric structure (with the same atoms surrounding the core atom), then chances are it does not have a dipole moment, while polar molecules do have dip...

Andre Fabian 1F

In determining melting and boiling point, we would look at intermolecular forces, given that these are formed between molecules. In order to change the state of a species, we must first excite or slow down the individual molecules in order for them to separate (i.e. increasing the temperature to exc...

Andre Fabian 1F

The lowest energy structure would be the one where the most atoms have a FC of 0 (or the lowest FC). For example, while comparing two resonance structures of the same species, if one has atoms with formal charges of +1, -2, +1 while the other has the formal charges of +1, -1, 0, the latter would hav...

Andre Fabian 1F

Hydrogen, like in everything else, is an exception to most rules.

A hydrogen atom has an electronegativity of 2.2, carbon 2.55, and fluorine 3.98.

2.55(C)-2.2(H)= 0.35
3.98(F)-2.55(C)=1.43

As 1.43 > 0.35, CF4 has a higher ionic character.

Hope this helps!

Andre Fabian 1F

https://imgur.com/I3yLLry
I'm really sorry for spamming this post but here's the imgur link^

Andre Fabian 1F

I'm hoping this time it's going to load

Andre Fabian 1F

https://imgur.com/a/OfSIUrC (since the photo isn't loading for me in the first post)

Andre Fabian 1F

Hi there! I'm stuck on question 17 of the Sapling weeks 7 & 8 homework.

I have to draw 3 resonance structures for C3H4. Can someone tell me what I'm doing wrong? I don't understand the feedback Sapling's giving me.

Thanks!

Andre Fabian 1F

The equation depends on the variables given in the question, as well as what you're trying to solve for. You can combine/relate these two equations with each other, in order to solve for particular values.

Hope this helps!
Andre

Andre Fabian 1F

Following what the above two people said, you should be able to work out the appropriate answer (using E = hc/lambda). However, I found something really weird with the problem where the first slot only accepted the really specific answer 1.03, and that when I rounded any number before that in my cal...

Andre Fabian 1F

In this context, a "Hamiltonian" represents a double derivative. Thus, the Schrodinger equation represents that the double derivative of the wave function (orbital) representing e- is equal to the Energy of the wave function (orbital) representing e-.

Hope this helps!
Andre

Andre Fabian 1F

My TA said that if there's any calculations, the required information to do such calculations would be provided, but as long as you know the general trends, you should be fine. I don't think Dr. Lavelle would try to pull anything tricky like that; in my experience any conceptual questions related to...

Andre Fabian 1F

Hi there! I'm not sure if this was the answer you're looking for, but when electrons absorb energy from outside sources (i.e. an incoming photon), they can jump to higher energy levels, such as from n=1 --> n=2. This topic was covered in the atomic spectra unit, so I wouldn't worry about it too much...

Andre Fabian 1F

Chi squared represents the probability of finding e-, and nodal planes are the possible locations for an e-.

Hope this helps!
Andre

Andre Fabian 1F

I'm not sure if this answers your question, but I remember hearing from the lecture that Group 13 elements need 5 valence e- to complete their octet. Since it's more difficult for them to gain that many valence electrons, they participate in coordinate covalent bonds, where the Group 13 element form...

Andre Fabian 1F

1/s = Hz

1 J = kg.m^2/s^2

Hope this helps!
Andre

Andre Fabian 1F

I believe so; atoms with similar numbers of valence electrons are organized together in groups (alkali metals, alkaline earth metals, halogens, noble gases, etc.); each group has similar properties (alkali metals being highly reactive with water, noble gases being extremely stable and unwilling to t...

Andre Fabian 1F

While acknowledging certain trends in the periodic table, such as going across a period and up a group are indicative of higher electronegativity levels, can be helpful, Lavelle mentioned that memorization of such values are not necessary. I believe we will be provided with the appropriate resources...

Andre Fabian 1F

To find the mass of a single molecule, you would divide its molar mass by Avagadro's constant (6.022 x 10^23). In addition, the masses found underneath each element in the periodic table are in amu, but we use them to calculate the molar mass of a certain molecule, in which we divide the grams used ...

Andre Fabian 1F

As the student above me mentioned, the wavelength and frequency of a certain photon are specific values that can be derived from each other. As each photon would have the same wavelength and frequency, their values would not be changed. However, as increasing the number of photons increases the inte...

Andre Fabian 1F

Atomic radii increases going down a group (additional shells are further from the nucleus), and decreases across a period (e- are in the same shell and the increasing nuclear charge pulls them in). Ionic radii demonstrate the same trends (increases in size down a group and decreases in size across a...

Andre Fabian 1F

Yes, the Lyman series always ends in n=1 (ground state), while the Balmer series always ends in n=2.

Hope this helps!
Andre Fabian

Andre Fabian 1F

Yes! This is true. Wavelengths and frequencies are inversely proportional to one another, as indicated by the following equation: c = (lambda) v. Since c, the speed of light, is a constant at 3.00 x 10^8 m/s, then it can be derived that if the wavelength of a photon increases, the frequency of the s...

Andre Fabian 1F

Hi I'm still confused over the difference between electron affinity and electronegativity. Do they effectively go hand in hand? Electron affinity is the amount of energy released after an atom or molecule gains an electron, and electronegativity is the ability of an atom to attract an electron. Hop...

Andre Fabian 1F

Photons have a constant speed, and their wavelength and frequency are related to each other through the equation c = λv, where c = speed of light (constant 3.00 x 10^8 m/s), λ = wavelength (in meters/nanometers), and v = the frequency (in Hz). E=pc is used when finding the energy of a particle in re...

Andre Fabian 1F

He briefly went over black bodies in his slides, but he mentioned that these topics would be covered in a more major-specific class. So thankfully, they're not going to be on the midterm.

Hope this helps!
Andre

Andre Fabian 1F

I agree with what everyone above said--the equation you listed should be correct. Make sure you have the parentheses at the right locations if you're using your calculator to solve, otherwise I think you're set!

Hope this helps,
Andre Fabian

Andre Fabian 1F

Both are correct, but you would use either depending on the context. A good way to check which one to use is to make sure that the units cancel out in whichever equation you're using, or that you don't have any units leftover that wouldn't apply to the answer.

Hope this helps!
Andre

Andre Fabian 1F

^bump^

Andre Fabian 1F

Hi, I also got around the same number of 1.60 *10^-19 J. You just need to convert that back into eV for eV/atom. Then to find the kJ/mol, you would convert the joules found previously (1.60*10^19) to kilojoules then multiply it by Avogadros's number to get the kJ/mol. Hope this helps! I'm still con...

Andre Fabian 1F

Hi there! To calculate the mass, you would divide the molar mass of N2 (given that nitrogen is only found in pairs in nature) by Avogadro's constant (6.022 x 10^23). This would give you the mass per molecule of N2. Before you substitute this value in the equation, don't forget to convert the g into ...

Andre Fabian 1F

Hi there! A black body is a substance that absorbs and emits all wavelengths. As such, because no light is reflected, black bodies are invisible to the eye. There are substances that exist that are very close property-wise to black bodies, yet there aren't any discoveries of actual substances meetin...

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