CHEMISTRY COMMUNITY

Eliana Carney 3E

Hey guys! I'm a little confused on parts A and D of the textbook problem 5.33. -For part A, I don't understand how you can tell the reaction is endothermic. Is this inferred because the reaction takes place at such a high temperature, or is there a concrete way to tell that the given reaction is end...

Eliana Carney 3E

Hey guys!
One of the bullet points on outline #1 for chemical equilibrium states "use equilibrium constants to predict solubility". Can someone explain the correlation between solubility and the equilibrium constant? Thanks in advance!

Eliana Carney 3E

Hey guys!
I'm having issues figuring out the value of n to use in the NERNST equation. If someone could explain how to get this value, it would be appreciated!

Eliana Carney 3E

Hey guys! When I was checking my answers for the textbook problem 6M.H, specifically part B, I noticed that the answer key did not include a calculation for ΔG°. I was wondering if this reaction doesn't have a value for ΔG° because the standard cell potential was negative? Or maybe the answer key is...

Eliana Carney 3E

Hi! My approach varies slightly from yours. This is how I have been solving these problems: 1. For acidic and basic solutions, balance atoms other than H and O atoms. 2. For acidic and basic solutions, balance O atoms with H2O. 3. For acidic and basic solutions, use H+ to balance H atoms. (You are ...

Eliana Carney 3E

Hey guys! I just wanted to double check that I am using the correct to approach to balancing half reactions in acidic solution vs basic solution. No matter if the half reaction is in acidic solution or basic solution, the first step is to balance any atoms other than H and O atoms. Once all other at...

Eliana Carney 3E

Hey Trevor! I believe that the difference between k and k' is that k' is calculated using data in which the concentrations of the reactants have been manipulated whereas k is calculated using data in which the concentrations of the reactants are more or less left alone (the concentrations of the rea...

Eliana Carney 3E

Hey Ashley! I'm pretty sure that you can look at the stoichiometric coefficients when determining molecularity. In lecture #24, Dr. Lavelle said that the reaction A+A→P is bimolecular. Another way of writing this reaction is 2A→P, and I believe that because the reactions are the same thing (just wri...

Eliana Carney 3E

In a reaction with multiple reactants, k' won't be the same for each reactant. k' appears in the rate law when a reaction has been manipulated to have one reactant in a much lower concentration than the others. Therefor, when you manipulate the concentration of different reactants, k' will be differ...

Eliana Carney 3E

Hey guys! I just want to double check and make sure I'm understanding the rate laws of elementary steps correctly. Essentially, all the molecules in elementary steps have to be colliding with one another and are therefor involved in the reaction. Using this information, you can write the rate laws o...

Eliana Carney 3E

Hey guys! In Lecture #24, Dr. Lavelle explained that if you have a reaction with multiple reactants, you can determine the rate of the reaction by making the concentration of one reactant very small compared to the others. I understand this experimental process for finding the rate law, but me quest...

Eliana Carney 3E

Hey Gabby! In order for Galvanic cells to function, there can't be a buildup of charge on either side of the cell so ions are actually flowing in both directions through the salt bridge or porous disk. Which way they are flowing depends on the positions of the anode and cathode. Anions are going to ...

Eliana Carney 3E

Would we be more focused on Galvanic cells for this section or do we memorize different how it applies to different cells? I think it would be best to try and remember how both Galvanic and electrolytic cells work and the differences between them. However, in lecture #20, I believe that Dr. Lavelle...

Eliana Carney 3E

Hey guys!
I'm a little confused on what exactly potential is. For example, when you say that the cathode has more potential than the anode, what does this mean? Does it have to do with its ability to pull electrons towards itself? Thanks in advance!

Eliana Carney 3E

Hey guys! I just wanted to clarify the difference between E° vs. E and G° vs. G. E° and G° are the potential and Gibbs free energy, respectively, for the system at standard conditions, and E and G are the potential and Gibbs free energy, respectively, for the system not at standard conditions? Basic...

Eliana Carney 3E

Hey guys! I'm a little bit confused on part of the content from lecture #17. In this lecture, Dr. Lavelle said that potential differences between electrodes causes electron movement. What exactly does he mean by potential difference? And what would cause an electrode to have more potential than anot...

Eliana Carney 3E

Hey Danielle! I don't think there is a set situation for which you would use either R value. Instead, which R value you use depends on the units you're dealing with. When R=0.08206, the units are (L.atm)/(K.mol). When R=8.314, the units are (J)/(K.mol). To decide which R value to use in a given situ...

Eliana Carney 3E

Hey Anya!

Personally, how I like to calculate degeneracy is with the formula W=x^n where x is the number of positions and n is the number of molecules. For example, if you have a mole of molecules with five possible positions, W=(5)^(6.022x10^23). Hope this helps!

Eliana Carney 3E

Hey Emily!
I believe that all exergonic reactions are spontaneous because the ΔG of an exergonic reaction is negative. Hope this helps!

Eliana Carney 3E

Hey guys! I'm having some trouble with question 7 in section 4D. The question reads: "Oxygen difluoride is a colorless, very poisonous gas that reacts rapidly and exothermically with water vapor to produce O2 and HF: OF2(g) + H2O(g) → O2(g) + 2HF(g). ΔH=-318 kJ. What is the change in internal e...

Eliana Carney 3E

Hey guys! I'm having some trouble with question 3 in section 4C. The question reads: Calculate the final temperature and the change in enthalpy when 765 J of energy is transferred as heat to 0.820mol Kr(g) at 298 K and 1.00 atm (a) at constant pressure; (b) at constant volume. Treat the gas as ideal...

Eliana Carney 3E

Hey Alex! You can use the formula ΔS=ΔH/T to solve this problem. Basically, because you are given the ΔS and ΔH for vaporization, you can plug the given values into this equation and solve for T because the temperature of vaporization is boiling point. One note is that you have to make sure that bot...

Eliana Carney 3E

Hey Molly! The inverse of a natural log is e, and you have to use this property to solve for K in this problem. What I did was take the formula ΔG∘r=-RTln(K) and solved for ln(K) first. When I did this, I got ln(K)=(ΔG∘r)/(-RT). Then I used the inverse logarithmic property for natural logs and solve...

Eliana Carney 3E

Hey Raquel! I believe that the most common unit for entropy is going to be J, however it really depends on the problem. One trick to make sure you are making your calculations with the correct units is to look at the units of the answer (which are given to us on both the Sapling problems and on the ...

Eliana Carney 3E

Hey Hana! Here's a list of the steps I took to solve this problem. 1. Convert the given temperatures from Celsius to Kelvin. 2. Calculate the number of moles present in the beginning of the reaction using the equation PV=nRT. When you solve for n, this equation becomes n=(PV)/(RT). 3. Calculate ΔS u...

Eliana Carney 3E

Hey guys! In lecture #15, Dr. Lavelle said that complex molecules have more entropy because complex molecules can have a greater number of different orientations for the atoms in the molecule. Given this information, would it be incorrect to say that molecules with resonance would have greater entro...

Eliana Carney 3E

Hey Brandon! The first thing you need to do to solve this problem is draw the Lewis structure for CO2 and decide wether it is a linear or nonlinear molecule. This will tell you what value to use for heat capacity. Once you've done this, you solve for q using the equation q=mcΔT where m is mass, c is...

Eliana Carney 3E

Hey Melody! Basically whatever R value you use depends on what units you're dealing with and what you're trying to solve for. If you want your final answer to be in L.atm, you would use the R value 0.0821 L.atm/K.mol. If you want your final answer to be in , you would use the R value 8.314 J/K.mol. ...

Eliana Carney 3E

Hey Olivia! For this problem, the first step is to solve for moles using the equation PV=nRT. Basically, you just substitute the given values for P (pressure), V (volume), and T (temperature) and R=0.0821 L*atm/mol*K to solve for n. For the volume, you have to substitute the original volume because ...

Eliana Carney 3E

Hey Melody! For this question, you have to use two equations. The first equation is U=q+w where U is internal energy, q is the energy going in or out of the system, and w is work. Because you are given values for internal energy and work, you can substitute them into the equation and solve for q. On...

Eliana Carney 3E

Hey guys!
I'm a little confused about what exactly internal energy actually is. If someone could define it or explain what the internal energy of a system is, it would be appreciated. Thanks in advance!

Eliana Carney 3E

Hey Lilyana! Basically, if the reaction is endothermic, then heating will favor product formation and increase K. If the reaction is exothermic, then heating will favor reactant formation and decrease K. I like to think of heat as either a product or a reactant depending on the reaction, and this he...

Eliana Carney 3E

Hey Sean! If the problem has a Kc value that is less than 1.0 x 10^-4, you can approximate that the value of X becomes negligible. You can do this because the small Kc value indicates that there is very little product formed at equilibrium, meaning that the concentration of the reactants isn't chang...

Eliana Carney 3E

Hey guys! I'm kinda confused on how to solve textbook problem 4D.23. For this problem, we are supposed to calculate the standard energy formation of dinitrogen pentoxide using two given equations and their standard reaction enthalpies. 1) 2NO(g) + O2(g) → 2NO2(g) ΔH=-114.1 kJ 2) 4NO2(g) + O2(g) → 2N...

Eliana Carney 3E

Hey guys! I'm a little confused on textbook problem #5.61, specifically part F. For this problem, we are supposed to predict the effect of a given change on the equilibrium composition of the equation 6CO2(g) + 6H2O(l) → C6H12O6(aq) + 6O2(g). Part F asks what would happen if more water was added. My...

Eliana Carney 3E

Hey guys! I have a few questions on textbook question #5.35. First of all, I don't understand how exactly to write the balanced equation for part a. I understand that the base equation is A(g) → B(g) + C(g) because the graph is showing the decomposition of A into B and C. What I don't really underst...

Eliana Carney 3E

Hey Victoria! Basically, we are allowed to round the equilibrium value in an ICE chart when Kc < 1.0x10^-3. One way to double check if rounding the equilibrium value in the ICE chart was appropriate is to make sure that the X value you calculated using the rounding is less than 5% of the initial con...

Eliana Carney 3E

Hey Aliya! Basically, the Ka value is a measurement of how much an acid dissociates in solution. Therefore, the higher the Ka value, the more the acid has dissociated, the higher the concentration of hydronium ions in solution, and the stronger the acid. Similarly, the lower the Ka value the weaker ...

Eliana Carney 3E

Hey Lilly! Essentially, whenever anything has a "p" in front of it, it is telling you to take the negative log of the given value. So yes, pKa is just the negative log of Ka. However, the two are related in the sense that a smaller pKa value means the Ka value is relatively large and vice ...

Eliana Carney 3E

Hey Cecilia!
I don't think you have to include the concentration of a solid in an ICE table because it's not included in the equilibrium constant. Hope this helps!

Eliana Carney 3E

Hey guys! I'm a little bit confused on the textbook question 5G.9, specifically part C. The question reads " A sample of ozone, O3, amounting to 0.10 mol, is placed in a sealed container of volume 1.0 L and the reaction 2O3(g) → 3O2 (g) is allowed to reach equilibrium. Then 0.50 mol O3 is place...

Eliana Carney 3E

Hey guys! I'm a little confused about a note Dr. Lavelle added in Lecture #6. Basically he said that, when calculating the pH of a weak acid or base, if the concentration of hydronium ions is less than 1x10^-7, we are to consider the solution neutral because autoprototlysis generates 1x10^-7M H3O+. ...

Eliana Carney 3E

Hey guys! I just wanted to make sure I am understanding how exactly to apply the conjugate seesaw. In lecture #5, Dr. Lavelle said that when you "add up" two chemical reactions, you get 2H2O(l) → H3O+(aq) + OH-(aq). I just wanted to clarify that the two chemical reactions you "add tog...

Eliana Carney 3E

Hey guys! I'm having a little bit of trouble on question #5 in the Week 2 Sapling homework. The question reads "The Kb for an amine is 5.320x10^-5. What percentage of the amine is protonated if the pH of a solution of the amine is 9.701?". -For starters, I wrote out a formula for the chemi...

Eliana Carney 3E

Hey guys! I'm a little confused on how to solve question #1 on the Week 2 Sapling homework. My question states "If the Ka of a monoprotic weak acid is 9.0X10^-6, what is the pH of a 0.14M solution of this acid?". I'm not really sure how to relate Ka to pH with the given information. If som...

Eliana Carney 3E

Hey guys!
A couple of the questions in the Week 2 Sapling homework say that a given substance is a monoprotic weak acid. I was wondering, what does monoprotic mean in terms of the acid? Thanks in advance!

Eliana Carney 3E

Hey Aishwarya! You are correct in saying that once a reaction reaches equilibrium the concentrations of products and reactants would stay the same. Essentially, when Q>K, some outside occurrence has occurred that has shifted the reaction out of equilibrium. For example, a change in temperature, the ...

Eliana Carney 3E

Hey Melissa, That is correct! We use Q when calculating the reaction quotient of a reaction that isn't at equilibrium. Because Q is calculated the same way as K ([P]/[R]), then if the reaction is at equilibrium the ratio of the concentrations of products to reactants would just be equal to K. If the...

Eliana Carney 3E

Hey Bronson, I don't believe that P/R is directly proportional to K (the equilibrium constant) using the ideal gas law. The ideal gas law states PV=nRT, which can be arranged to state n/V=P/RT. This can also be written as concentration=P/RT. While both this rearranged ideal gas law and K deal with c...

Eliana Carney 3E

Hey guys! I just wanted some clarification of why exactly increasing pressure by adding an inert gas doesn't move the reaction from equilibrium. I understand that the reaction doesn't move from equilibrium because the concentrations of the reactants and products don't change. Where I get confused is...

Eliana Carney 3E

Hey guys! In Lecture #2, Dr. Lavelle mentions we are going use the ideal gas law for all gases when dealing with equilibrium calculations. I'm a little confused as to what exactly an ideal gas is? If someone could explain what an ideal gas is and how it is different than a non-ideal gas that would b...

Eliana Carney 3E

Hey guys! I'm a little confused on textbook question 6.5, specifically part C. If someone could explain why H2O2 is the Lewis base and SO3 is the Lewis acid, that would be appreciated!

Eliana Carney 3E

Hey guys! I'm unsure about how to write the chemical formulas for the aqueous solutions in textbook question 6D.11. Specifically, I don't understand how to write the equations for part E and F. If someone could explain where the answer key got the additional water molecules attached to the metal cat...

Eliana Carney 3E

Hey guys! I'm kinda confused on how to determine wether or not a compound is acidic, basic, or amphoteric. If someone could explain to me why, in question 6A.17, BaO is basic, SO3 is acidic, and As2O3 and Bi2O3 are ampotheric that would be great. Also, if there are any guidelines for determining if ...

Eliana Carney 3E

In a lot of the textbook problems that go along with the acid and base section, we were supposed to either know the formula of an acid from its name or name an acid from its formula. I don't remember going over this in class. I'm not sure if I either missed it in lecture or if we actually didn't go ...

Eliana Carney 3E

Hey guys! The textbook problem question 6A.3 deals with writing chemical equations and identifying the conjugate acid-base pairs. I just wanted to make sure that I am understand parts b and d correctly. For part b, you have to write the chemical equation for anilinium ion (C6H5NH3+), in water. I jus...

Eliana Carney 3E

Hey guys! I'm a little confused on question 2.45 from the textbook. I understand how to draw the Lewis structure and identify the sigma and pi bonds. Where I get confused is the hybridization of each lone pair. Specifically, what I don't understand is where the number before the hybridization comes ...

Eliana Carney 3E

Hey Arubal! In Lecture #24 Dr. Lavelle talks about a chemotherapy drug called cisplatin. I would assume this is what the syllabus is referring too, especially since the textbook doesn't talk about any additional chemotherapy drugs. Basically, we learned that the coordination compound cisdiamine-dich...

Eliana Carney 3E

Hey Jolie! Basically the general "formula" if you will for naming coordination compounds is Greek prefix-ligand name + transition metal cation name (roman numeral) + anion name + Greek prefix-hydrate. This is slightly confusing just looking at it, but once you get the hang of naming it get...

Eliana Carney 3E

Hey guys! In Lecture #26, Dr. Lavelle said that the Bronsted definition of acid and bases isn't as fundamental as the Lewis definition because not every reaction involves protons. I'm a little confused on how a chemical reaction involving an acid or a base can take place without the involvement of p...

Eliana Carney 3E

Hey guys! I was hoping that one of you can clarify why exactly something is a proton donor or a proton acceptor. I was thinking that a molecule is a proton donor and therefor a Bronsted acid when one of its hydrogens forms a hydroxide ion because the protons in said hydrogen and being transferred (o...

Eliana Carney 3E

Hey guys! I just wanted to clarify something about naming anions that interact with coordination compounds. On Sapling, I had to name [Co(NH3)5Cl]Cl2. I understand how to name the coordination compound inside the brackets, but I was a little confused about how to name the anion outside the brackets....

Eliana Carney 3E

Hey Queena! A sigma bond occurs when two orbitals interact end-to-end and form a bond. A pi bond occurs when two orbitals overlap side-by-side and form a bond. Pi bonds can only form if an atom's electron configuration includes a d-orbital because without a d-orbital there is only one orbital, the s...

Eliana Carney 3E

Hey Jade! I think where you are going wrong is the number of bonds on carbon. Remember carbon's electron configuration does not have a d-orbital so a carbon atom cannot have more than four bonds. Taking this into consideration, all you have to do is move one of the hydrogens that is bound to the car...

Eliana Carney 3E

Hey Jessica! Essentially hybridization is very similar to what the name suggests. In hybridization, the orbitals of an atom are hybridizing or, in other words, mixing together. Basically, when bonding, atoms may not have enough unpaired electrons in their valence orbitals to create the bonds they ne...

Eliana Carney 3E

Hey guys! I was just wondering why some people write the hybridization of an atom like dsp^3 and not sp^3d? I was thinking that maybe people write the hybridization like dsp^3 with the 'd' out front because, in electron configurations, the d-orbitals fill up after the s-orbitals. If someone could le...

Eliana Carney 3E

Hey Emily! You are correct in saying that lone pairs do influence molecular shape. The amount of lone pairs and amount of bonding pairs both contribute to the molecular shape of a molecule (even though naming has to do with the amount of bonding pairs). What the textbook means by stating "Elect...

Eliana Carney 3E

I'm pretty sure that when determining which ionic molecules display the most covalent character, you just look at the difference in electronegativity. The smaller the difference in electronegativity, the more covalent character the molecule has and vise versa. One way to determine this without the e...

Eliana Carney 3E

Hey Jaclyn! The formula for formal charge that Dr. Lavelle gives in lectures is: formal charge = valence electrons - ((shared electrons/2) + lone pair electrons). While this formula works, it is a little hard to remember. Instead of this formula, I like to think of formal charge as: formal charge = ...

Eliana Carney 3E

Hey guys! I have a question regarding expanded octets. I understand that atoms of elements in period three or below have d-orbitals in their valence shells that can accommodate more than 8 electrons. What I don't understand is exactly how many more electrons these elements can accommodate/how many m...

Eliana Carney 3E

Hey guys! I don't understand how exactly the strength of an induced dipole-induced dipole interaction and boiling point relate to each other. If you could explain how these two correlate and how you would go about figuring out the boiling point of a substance (or rather figuring out if it has a high...

Eliana Carney 3E

Hey guys! I'm quite confused about the trends for polarizing power on the periodic table. I understand that polarizing power decreases as you go down a period on the periodic table because the radius of the atom increases and therefor the nucleus' pull on the electrons is not as strong. Where I get ...

Eliana Carney 3E

Hydrogen bonds aren't a concrete bond, but rather a favorable electrostatic attraction. This attraction has an energy of approximately -20 kJ/mol.

Eliana Carney 3E

Hey guys! In Lecture #18, Dr. Lavelle talks about how the shape of molecules contributes to the total strength of the interaction. While I understand how the shape of molecules correlates to the strength of the interaction, I'm confused on what the strength of the interaction actually means. It is r...

Eliana Carney 3E

Hey guys! I'm a bit confused on how exactly the strength of dispersion forces relates to the number of electrons and the state of the substance. In Lecture #18, Dr. Lavelle says that the strength of dispersion forces explains why elements are at different states at room temperature. He says that thi...

Eliana Carney 3E

Hey guys! I just want to make sure I'm understanding electron distortion and polarizing power correctly. Basically, in an ionic bond the cation exerts electrostatic attraction on the electrons surrounding the anion, pulling the electrons towards itself and therefor distorting them? And when looking ...

Eliana Carney 3E

In Lecture #14, Dr. Lavelle introduced the idea that the electrons involved in resonance are delocalized. My question is, what does it mean when an electron is delocalized? Thanks in advance!

Eliana Carney 3E

Hey Noelle! Resonance is the idea that Lewis structures can have multiple bonds (ie not single bonds) in different locations. Basically, if you're looking at a Lewis structure and it has a multiple bond that can be placed somewhere else without creating a different molecule, there is resonance. This...

Eliana Carney 3E

Hey Alison! The first thing to know when calculating formal charge is the formal charge equation. The equation is as follows: formal charge = V (number of valence electrons for the bound atom) - ( (shared electrons/2) + L (number of lone pair electrons)) In this lecture, Dr. Lavelle calculated the f...

Eliana Carney 3E

In the formal charge equation, L represents the number of lone pair electrons on the given bound atom. To find L given a Lewis structure, you just count the number of dots next to the atom. The number of dots is equal to the value L. Hope this helps!

Eliana Carney 3E

Hey guys! I just had a quick question from Lecture #14. When talking about delocalized electrons, Dr. Lavelle says that benzene is more stable than a molecule with three separate and identifiable single bonds and three separate and identifiable double bonds. In regards to the molecule benzene is bei...

Eliana Carney 3E

Hey guys! I just want to make sure that I truly understand the octet exception for the first four elements. When looking at the electron configurations for these elements, the valence electron is in the s subshell (1s for H and He and 2s for Li and Be), and this is why these elements defy the octet ...

Eliana Carney 3E

Hey Jenny! The answer to your question can be found by looking at the electron configuration of oxygen, nitrogen, and fluorine. Nitrogen has 3 electrons in the 2p subshell, oxygen has 4 electrons in the 2p subshell, and fluorine has 5 electrons in the 2p subshell. According to Hund's Rule, nitrogen ...

Eliana Carney 3E

Hey Sahiti! To answer this question, you have to remember two things. First of all, the ionic radius of a cation is going to be smaller than the radius of the parent atom because the electrostatic attraction is going to be higher per electron, thus pulling the electrons in tighter to the nucleus. Th...

Eliana Carney 3E

In Lecture #11, Dr. Lavelle talks about how electrons will enter the 4s orbital before the 3d orbital because it requires less energy. I understand this, but what I don't understand is how, for multi-electron atoms with an atomic number larger than 20, the 4s orbital is higher in energy than 3d. How...

Eliana Carney 3E

Hey guys! I'm a little confused about how exactly you calculate the possible values for M(L) given L. Just to make sure I'm understanding it correctly, the possible values for M(L) are the range of whole numbers between positive L and negative L? For example, if L=3, the possible values for M(L) are...

Eliana Carney 3E

In my notes from Lecture #8, I wrote "The wave model explains why electrons have quantized energy states in atoms as observed by experimental observation". Upon reviewing, I am confused as to how exactly the wave model relates to the quantized energy states of electrons. If someone could e...

Eliana Carney 3E

Hey Natalie! I'm a little confused with what you mean here, so I'll tell you what I did for question 1B.21 and maybe it will match up to your though process. First, I converted the given mass (5.15 oz) from ounces to grams. I also converted the given velocity (92 mi/h) from miles per hour to meters ...

Eliana Carney 3E

Hey Melody! The first step to this problem is calculating the uncertainty of the bowling ball's momentum using the formula: Δp = (mass(m)) x Δv. The uncertainly of the velocity is going to be 5.0 m/s because as the problem states, the velocity is 5.00 ± 5.0 m/s. This shows that the uncertainly in ve...

Eliana Carney 3E

Hey Marcus! The first thing you must do for this problem is convert the diameter of the atom from pm to m. Then, you plug in values to the Heisenberg indeterminacy equation that states (Δp)(Δx) ≥ (h/(4π)). You are solving for Δp. Δx is equal to the diameter of the atom in meters, and h is Plank's co...

Eliana Carney 3E

The sign for the energy switched from negative to positive because the first calculations gave us the energy lost by the electron as it transitioned between the levels. The sign for this energy is negative because the energy was lost. The sign for the energy then switched to positive because we were...

Eliana Carney 3E

Hey Evonne! To solve part A, you first find the electron's momentum using the formula: momentum(p) = (mass(m)) x (velocity(v)). Make sure to convert the given velocity from kg/s to m/s. Then, you use the momentum to find the energy of the electron with the formula: energy(E) = (momentum(p)) x (speed...

Eliana Carney 3E

Yes, the work function (which is also referred to as the threshold energy) is the amount of energy needed to remove an electron from a given metal during a photoelectric experiment.

Eliana Carney 3E

This equation is used to calculate the kinetic energy of an electron, also known as the excess energy, in a photoelectric experiment.

Eliana Carney 3E

Hey Isabel! There are actually only two formulas you need to complete this problem so it's not too complicated once you get them. -The first formula is the formula for wavelength. The formula is wavelength = (c (speed of light)) / (v (frequency)). Just a note, the speed of light is equal to 3.00 x 1...

Eliana Carney 3E

Electrons are excited during atomic spectroscopy when they go from one energy level to another. They are ejected during the photoelectric experiment when the goal is to measure how much energy is required to remove electrons from different metals.

Eliana Carney 3E

Just to clarify, when talking about increasing the light intensity during the photoelectric experiment, the scientists were just increasing the brightness of the light? They weren't changing the frequency/wavelength of the light?

Eliana Carney 3E

Hey! The first step to completing this problem is finding the number of silver atoms in 1.00 mol Ag because you need to know how many atoms you are connecting. This is a simple conversion using Avogadro's number (the number of atoms/molecules in one mole of a substance). All you do is multiply 1.00 ...

Eliana Carney 3E

Hey! This problem is actually easier than you might think. I know I was overthinking it before I realized that it's just multiplication and subtraction. The first thing you have to do is figure out the mass of calcium chloride. It is given than the mixture contains 32.5% calcium chloride, so all you...

Eliana Carney 3E

Hey! This problem took me a while to figure out too, so you're not alone haha. Anyways, the first thing I did was figure out the molarity of the diluted solution. I did this by multiplying the original molarity, 0.10 M, by (1/2)^90 because you are diluting the original molarity by half each time you...

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