CHEMISTRY COMMUNITY

Cynthia Bui 2H

O2 by itself has a charge of 0 but in a compound/molecule you consider how O's charge is 2- so it goes from 0 to 4- charge.

Cynthia Bui 2H

I'm not quite sure if this is what you wanted but if for the second one its from H3O+ to O2, then the O is going from 1+ to 0, so it would be reduced and the oxidizing agent.

Cynthia Bui 2H

Yes, electrolysis is when an electric current is used to drive a non spontaneous reaction which is often when e- need to flow towards the anode for this to occur. The current is simply directed towards the anode (or site w lower E cell) to provide the right energy.

Cynthia Bui 2H

The more negative the E is, the better it is as a reducing agent and vice versa.

Cynthia Bui 2H

Electrons provide the activation energy that is normally too high for the reaction to be spontaneous.

Cynthia Bui 2H

In terms of their oxidizing power, it means that the more it will take e- the stronger its oxidizing power, so the greater and more positive E is the greater it's oxidizing power.

Cynthia Bui 2H

The reducing agent is the one that causes another molecule to be reduced, meaning the other molecule GAINS an electron and the reducing agent is the one that gave an electron (or more) up. So, looking at AgF, for it to be neutral, Ag had to be 1+ and it shows when they separate, Ag is neutral, so it...

Cynthia Bui 2H

They're both state functions. Because of that you can add their quantities together to get a total or final entropy or enthalpy.

Cynthia Bui 2H

deltaS total = 0

Cynthia Bui 2H

I don't think there is one. It mainly depends on the numbers you have available to you.

Cynthia Bui 2H

This is total entropy, not change in entropy which is what we normally tend to calculate. You would use this when given a number of molecules and the possible orientations they can lay in and such. For example if a solid had 64 molecules and the molecules can like in any 4 directions, W= 4^64

Cynthia Bui 2H

Depends on the heat capacity you use. Always write out your units to make sure you're using the right value!

Cynthia Bui 2H

If the slow step is first, the reaction is determined by the slow step but if it is second, you use the pre-equilibrium steps we learned.

Cynthia Bui 2H

The line would be parallel to the x-axis.

Cynthia Bui 2H

A reaction can be negative with respect to one reactant but I don't think all reactants can have a negative order. The overall order for a reaction has to be at least 0.

Cynthia Bui 2H

Slope is -K, a downward sloping graph.

Cynthia Bui 2H

No, they're not considered vacuums.

Cynthia Bui 2H

Yeah, he had this one slide with their names that you had to identify. They were alcohol, ether, aldehyde, ketone, carboxylic acid, and amine.

Cynthia Bui 2H

Any energy that is not used to eject the electron (assuming the photon's energy is above the threshold) goes towards the electron's kinetic energy. So, normally, KE = Photon's E - threshold E, but you just need to rearrange to get the threshold energy.

Threshold = Photon's E - KE

Cynthia Bui 2H

Like another poster said, the electrons in the current provide energy.

Cynthia Bui 2H

n = number of electrons

Cynthia Bui 2H

We can change q to deltaH because in reversible situations, the change in potential thermal energy IS the amount of heat transferred. Even though they are different things in these cases they are equivalent.

Cynthia Bui 2H

Like everyone's said, it's the energy available to do work. So when it change in G is negative, the reaction is spontaneous because that means there was enough energy to complete the reaction after accounting for changes in entropy.

Cynthia Bui 2H

You feel cold when heat is flowing out of you and feel warm/hot when heat is flowing into you (say your hand when you hold a hot cup of tea). The temperature decreases when you add ice because heat is being transferred into the ice away from the liquid, lowering the temperature of the liquid.

Cynthia Bui 2H

The more degrees of freedom a molecule has the higher its heat capacity.

Cynthia Bui 2H

Definitely Kelvin.

Cynthia Bui 2H

From what I know, the content from Outline 1 and Outline 2 on his website will be covered in the midterm. No electrochemistry.

Cynthia Bui 2H

Would an insulated lunchbox be an isolated system? Curious because I misread the test question as a "pack" being a lunch pack/box instead of an... actual cold pack. Whoops.

Cynthia Bui 2H

And to expand on what Sungyoon said, the system does not want to change. It wants to stay at a certain equilibrium of conditions, so when the volume is decreased, the temperature will decrease so that the pressure remains constant. By decreasing the temp, the molecules will collide at the same rate ...

Cynthia Bui 2H

The change in enthalpy isn't the change in heat without work, it refers to the transfer of heat at a constant pressure, which implies that work is being done. Enthalpy is the total energy content of a system so the change in enthalpy is equal to the change in internal energy due to transfer of heat ...

CHEMISTRY COMMUNITY

Search found 30 matches

Re: Test 2 #1

Re: Eletro chem Test

Re: Electrolysis

Re: Reducing Agent/ Oxidizing Agent

Re: Electrolysis

Re: Test #2 Question 5

Re: Reducing and oxidizing agents

Re: State functions?

Re: reversible system

Re: Difference between calculations

Re: S=klnW

Re: mass in q = m(c) delta t

Re: Slow Step in Reaction Mechanisms

Re: graph of 0 order

Re: Negative Orders

Re: Slope of 1st order RXNs

Re: Bomb Calorimeter

Re: Final

Re: Test 2, #7a

Re: Electrolysis

Re: Finding n

Re: phase change change in entropy

Re: what exactly is free energy?

Re: Concept of "Cold"

Re: Heat Capacity [ENDORSED]

Re: Celsius or Kelvin

Re: Midterm

Lunchbox?

Re: Pressure's Relationship with Volume

Re: Enthalpy