CHEMISTRY COMMUNITY

Alexa Tabakian 1A

Make sure the order of the reaction corresponds to the right half-life equation.

Alexa Tabakian 1A

You use this equation when you either have activation energy or need to find it.

Alexa Tabakian 1A

How would you draw a reaction profile for the reaction? Do we need to know how to do this?

Alexa Tabakian 1A

You should know how to get from the first equation to the last equation. Both of these will be given, but you should know how the last equation is derived from the first equation.

Alexa Tabakian 1A

Steam has a higher enthalpy because it takes more energy and heat to keep it as a gas. Therefore, it causes worse burns.

Alexa Tabakian 1A

Yes, it is a second order reaction because the exponents that you multiply by in the rate equation add up to 2.

Alexa Tabakian 1A

Yes, delta S can be both positive and negative.

Alexa Tabakian 1A

All E cell values are reduction values. You can either flip the sign for oxidation or use the formula Ecell= Eright-Eleft

Alexa Tabakian 1A

It is 0 because water vaporizes at 100 degrees, therefore, the system is technically in equilibrium because the question asks for the delta g of vaporization.

Alexa Tabakian 1A

On some of the homework solutions, they add a completely random element to the cell diagrams. For example, on 14.15, the cell diagram shows KOH, however there is no KOH in the solution. Can someone please explain?

Alexa Tabakian 1A

Use the charges from the periodic table! Hope this helps!

Alexa Tabakian 1A

Which is the thermodynamically more stable iron oxide in air, Fe3O4(s) or Fe2O3(s)? Justify your selection.

How do you know, is it based on the molecular mass?

Alexa Tabakian 1A

What amount (in moles) of ATP could be formed if all the Gibbs free energy released in the oxidation of 3.00 mol NADH were used to generate ATP?

I do not know how to approach this problem given just three equations and delta G. Can anyone help me out?

Alexa Tabakian 1A

delta S equals zero when the reaction is reversible because entropy is a state function. When the process is reversible, it starts and ends in the same place making entropy equal to zero.

Alexa Tabakian 1A

Their heat of formation is zero because they are in their most stable state, that is why they are not included.

Alexa Tabakian 1A

Heat capacity is extensive because it depends on the number of particles you have. Specific heat capacity and molar heat capacity are intensive because it is uniform for all molecules. For example, the specific heat of water is always 4.184 J/G x C and it does not matter how much water you have.

Alexa Tabakian 1A

The book says container A has the most entropy, then C, then B.

Alexa Tabakian 1A

Container A is filled with 1.0 mol of the atoms of an ideal monatomic gas. Container B has 1.0 mol of atoms bound together as diatomic molecules that are not vibrationally active. Container C has 1.0 mol of atoms bound together as diatomic molecules that are vibrationally active. How do you determin...

Alexa Tabakian 1A

I noticed the problems in the book have a distinct way they would prefer you to solve them. For example, to use the version where you break down the different reactions, the book gives you the equations. Hope this helps!

Alexa Tabakian 1A

Yes, the pressure you would use to find n is 1.79 atm.

Alexa Tabakian 1A

There is w=-PdeltaV, w=nRTln(V2/V1), and w=nRTln(P1/P2)
The first one would be used for constant pressure and irreversible reactions. The second and third ones would be used in isothermic reversible expansions.

Alexa Tabakian 1A

The first one is for reversible expansion, and the second one is for irreversible expansion.

Alexa Tabakian 1A

Calculate the heat released by 5.025 g of Kr at .400 atm as it cools from 97.6 to 25.0 C at (a) a constant pressure and (b) constant volume.

I tried looking this up in the book and it wants to us to use fractions and stuff like that. Is there another way we learned how to do it in class?

Alexa Tabakian 1A

You still use the 101.325 J to convert from L x atm to Joules. You should get -150.97 Joules for work and then convert it to kJ which is -.15 kJ, this is work. You then add work and q which is 5.5 kJ. Your final answer should be 5.35 kJ.

Alexa Tabakian 1A

When volume is decreased at equilibrium, the reaction will shift to the side with less moles. It also depends on how Q relates to K.

Alexa Tabakian 1A

How would we go about finding the final temperature of HCl if the initial temperature is 25 degrees Celsius? What do you do with the volume and molarity you are given?

Alexa Tabakian 1A

We talked about it in lecture, so I'm assuming we need to know how to solve problems.

Alexa Tabakian 1A

I have no idea how to approach this problem. If somebody could please explain how to solve how much work is done, I would really appreciate it.

Alexa Tabakian 1A

If they give Kp, convert it to atm or bar, but if it gives Kc leave it in terms of the molar concentration.

Alexa Tabakian 1A

You can also tell if it is an acid or base based on the equation. If it gives off OH-, then it is a base, and if it gives off H3O+, it is an acid.

Alexa Tabakian 1A

The concentration of H2 would increase because there is now more CO that is available to react. Also, the concentration of H2 would increase in order to keep the equilibrium constant the same.

Alexa Tabakian 1A

A weak acid has a higher pH. A pH of 7 is neutral, so the weaker the base, the closer to 7 it gets.

Alexa Tabakian 1A

I'm confused on how to set up the equation to get H30+ if we are only given one number which is Kw. Can someone please explain?

Alexa Tabakian 1A

When the coefficient is not equal to one you would simply add the coefficient in front of the x. For example if you had 2H2 you would subtract or add 2x.

Alexa Tabakian 1A

I believe you use the units that are given and you just use a constant that corresponds to the units that are given.

Alexa Tabakian 1A

I was wondering how to set up the ICE table for this reaction. Do we have to convert into mol/L? Also do we assume that we start with no NH3 or CO2?

Alexa Tabakian 1A

Q would be anything other than equilibrium, and K is the equilibrium.

Alexa Tabakian 1A

I was wondering if anyone could explain how to find the partial pressures of N2, H2, and NH3 when only given that K=41. Do we have to involve constants from a table?

CHEMISTRY COMMUNITY

Search found 38 matches

Re: 15.31 6th Edition

Re: Arrhenius Equation.

15.89

Re: Integrating

Re: Steam vs Boiling Water

Re: Zero, First, and Second Order reactions

Re: Entropy of Fusion

Re: flipping the sign of Ecell

Re: Delta G at boiling point

Cell Diagrams

Re: Finding Charge

9.81

9.69 in Sixth Edition

Re: When is delta S = 0?

Re: Std Enthalpy of Formations

Re: Extensive vs Intensive

Re: 9.35 Sixth Edition

9.35 Sixth Edition

Re: Reaction Enthalpies

Re: Which P to use? 6th edition, 8.27

Re: Work Equations

Re: w=-PdeltaV

8.31 Sixth Edition

Re: 6th Edition, 8.9

Re: Decreasing volume and chemical equilibrium

8.99 in Sixth Edition

Re: Calorimeters

8.3 6th Edition

Re: How to know when to use partial pressure or molar concentrations?

Re: Acids and Bases

Re: 7th Edition 5J.1

Re: Acid and Base Equilibria

12.23 in sixth edition

Re: ICE tables

Re: Calculating Kp

11.41 in 6th edition

Re: Concentrations of products/reactants

11.37 6th Edition