Search found 27 matches

Thu Jan 14, 2016 9:26 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: units of hess's law, bond enthalpy, standard enthalpy
Replies: 1
Views: 493

units of hess's law, bond enthalpy, standard enthalpy

Can someone clarify what the units of the final answer will be for Hess's Law, Bond Enthalpies, and Standard Enthalpies of Formation problems, please?
Sat Jan 09, 2016 9:35 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.63C
Replies: 1
Views: 267

8.63C

Is there an error in the solutions for this problem because isn't the enthalpy of formation for K2S(aq) -471.5kJ/mol instead of -417.5kJ/mol?
Sat Jan 09, 2016 6:20 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Sig figs and thermodynamics
Replies: 2
Views: 405

Re: Sig figs and thermodynamics

for some final answers the solutions does not give it with respect to significant figures
Sat Jan 09, 2016 5:19 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: reason for omitting 8.55
Replies: 1
Views: 247

reason for omitting 8.55

Are we omitting problem 8.55 because the O2 does not cancel out and there still remains (1/2) O2(g)?
Sat Jan 09, 2016 5:16 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: calculating reaction enthalpy
Replies: 3
Views: 440

Re: calculating reaction enthalpy

thank you!
Sat Jan 09, 2016 5:16 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Sig figs and thermodynamics
Replies: 2
Views: 405

Sig figs and thermodynamics

Just a clarification: you always have to consider significant figures for the final answer, correct?
Thu Jan 07, 2016 8:59 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: calculating reaction enthalpy
Replies: 3
Views: 440

calculating reaction enthalpy

Will there be cases when calculating the reaction enthalpy in which we will need to balance one of the equations for the data given?
Thu Jan 07, 2016 8:56 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy
Replies: 3
Views: 553

Re: Enthalpy

thanks!
Wed Jan 06, 2016 4:30 pm
Forum: Phase Changes & Related Calculations
Topic: Enthalpy
Replies: 3
Views: 553

Enthalpy

Why exactly is enthalpy a state property?
Mon Jan 04, 2016 9:30 pm
Forum: Phase Changes & Related Calculations
Topic: ammonium nitrate dissolution
Replies: 2
Views: 706

ammonium nitrate dissolution

Can someone please explain how the dissolution of ammonium nitrate in water is endothermic? Thanks!
Fri Dec 04, 2015 10:37 am
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: HomeworkQuestion 13.11 part b
Replies: 1
Views: 268

HomeworkQuestion 13.11 part b

When you add 20.0ml (.020L) of .100M HNO3 to the initial buffer (acetic acid with .100M and 100.ml or .100L) what is the ph change? So first you find the concentration of HNO3 and then than of acetic acid but I got confused in the solution how come they add 1.00x1^-2 to the new mol of acetic acid. W...
Fri Dec 04, 2015 10:36 am
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: HomeworkQuestion 13.11 part b
Replies: 1
Views: 443

HomeworkQuestion 13.11 part b

When you add 20.0ml (.020L) of .100M HNO3 to the initial buffer (acetic acid with .100M and 100.ml or .100L) what is the ph change? So first you find the concentration of HNO3 and then than of acetic acid but I got confused in the solution how come they add 1.00x1^-2 to the new mol of acetic acid. W...
Sun Nov 29, 2015 9:34 am
Forum: Conjugate Acids & Bases
Topic: Homework Problem 12.59B
Replies: 1
Views: 293

Homework Problem 12.59B

For the percentage deportation of problem 59b I keep getting 1.5% but the solutions manual has 2.5% even though we both have it worked out the same way. Dis anyone else have this problem?
Mon Nov 16, 2015 7:41 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: hw problem 11.39
Replies: 3
Views: 516

Re: hw problem 11.39

thanks!
Mon Nov 16, 2015 7:40 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.67 Why do we use a new initial value?
Replies: 4
Views: 374

11.67 Why do we use a new initial value?

can someone please explain why there is an original and a new initial?
Sun Nov 15, 2015 3:48 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: hw problem 11.39
Replies: 3
Views: 516

hw problem 11.39

Mon Nov 09, 2015 6:34 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium constant and cubic equations
Replies: 1
Views: 419

Equilibrium constant and cubic equations

Will the equilibrium constant for a cubic equation always be a small number?
Mon Nov 09, 2015 6:29 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium constant and p
Replies: 5
Views: 432

Re: Equilibrium constant and p

For some homework problems like 11.3, the solutions include p in the answer but for other homework problems like 11.9 it doesn't. Is there a way that Dr. Lavelle wants us to do on the quiz and final?
Mon Nov 09, 2015 6:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Activity
Replies: 2
Views: 244

Re: Activity

thank you.
Sun Nov 08, 2015 11:57 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Activity
Replies: 1
Views: 271

Activity

I'm having trouble understanding the concept of activity. What exactly is it?
Sun Nov 08, 2015 11:57 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Activity
Replies: 2
Views: 244

Activity

I'm having trouble understanding the concept of activity. What exactly is it?
Sun Nov 08, 2015 11:50 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium constant and p
Replies: 5
Views: 432

Equilibrium constant and p

Will we always have to write P when writing the expression for the equilibrium constant?
Sat Oct 31, 2015 9:43 pm
Forum: Bond Lengths & Energies
Topic: MO Diagrams
Replies: 1
Views: 299

MO Diagrams

How does the energy difference between smaller nuclear charge gets smaller in MO Diagrams?
Sun Oct 25, 2015 9:44 pm
Forum: Hybridization
Topic: Shape
Replies: 2
Views: 350

Shape

How come resonance makes no difference in molecular shape?
Mon Oct 12, 2015 4:59 pm
Forum: Resonance Structures
Topic: Bond Angle
Replies: 2
Views: 401

Bond Angle

Does it matter what angle you place the bonds at?
Thu Oct 08, 2015 8:19 am
Forum: Quantum Numbers and The H-Atom
Topic: N increase
Replies: 2
Views: 404

N increase

How does an increase in n increase energy levels?
Sun Oct 04, 2015 1:12 pm
Forum: Properties of Light
Topic: Speed
Replies: 3
Views: 567

Speed

The book sometimes uses 2.998x10^8 m/s and other times 3.00x10^8 m/s? Which one will be using?