## Search found 21 matches

Sun Feb 28, 2016 2:07 pm
Forum: *Cycloalkenes
Topic: Intro to Organic Chemistry Question 1.21
Replies: 5
Views: 685

### Intro to Organic Chemistry Question 1.21

The answer to part a in the book says that the name of the cycloalkene is 5-methylcyclopenta-1,3-diene. Can you also write the name like 5-methyl-1,3-cyclopentadiene?
Mon Feb 08, 2016 5:11 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode and Cathode
Replies: 1
Views: 366

### Anode and Cathode

How can I tell which half-reaction will be the cathode and which will be the anode?
Mon Feb 08, 2016 4:35 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.13 part D
Replies: 1
Views: 320

### 14.13 part D

I'm confused as to why the Au3+ is put into a half reaction involving Au when they are both products of the overall reaction, Au+(aq)---------->Au(s)+Au3+(aq).
Sun Feb 07, 2016 11:31 am
Forum: Balancing Redox Reactions
Topic: Question 14.5
Replies: 1
Views: 243

### Question 14.5

For part a of this question, how do you figure out that O3 is the oxidizing agent and Br- is the reducing agent? The redox equation is O3(aq)+Br-(aq)--------->O2(g)+BrO3-(aq).
Mon Jan 25, 2016 9:53 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Residual Entropy
Replies: 5
Views: 1301

### Re: Residual Entropy

Can someone explain this further? I don't really understand this answer.
Mon Jan 25, 2016 4:48 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Moles in Hess's Law
Replies: 1
Views: 411

### Re: Moles in Hess's Law

You don't need to divide the 2NO2 by 2 because the final reaction you get is N2(g)+2O2(g)------> 2NO2. This is a balanced equation, so the net enthalpy is 68 kJ.

If you wanted to find the enthalpy per mol of NO2, then you would divide 68kJ by 2.
Mon Jan 25, 2016 4:43 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Enthalpy and Mass Question
Replies: 1
Views: 356

### Re: Enthalpy and Mass Question

The standard enthalpy for propane is given, -2220. kJ/mol. We can see that this is the amount of kJ needed to heat a mole of propane. So in order to find the mass of propane need to supply 2580 kJ of heat you need to divide 2580kJ by 2220. kJ/mol to obtain the moles of propane needed, \frac{2580kJ}{...
Mon Jan 25, 2016 4:18 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Quiz 1 Prep Winter 2015 Q 10
Replies: 1
Views: 331

### Quiz 1 Prep Winter 2015 Q 10

Can someone explain which equation(s) you need to use for this question and why?
Mon Jan 18, 2016 5:04 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Question 8.49
Replies: 1
Views: 314

### Question 8.49

How do I know that the temperature for the equation PV=nRT is 298K in this problem?
Mon Jan 11, 2016 5:58 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Question 8.31
Replies: 1
Views: 270

### Question 8.31

For question 31, how do you find the heat capacity of Kr at a constant pressure and then at a constant volume?
Mon Jan 11, 2016 12:14 pm
Forum: Calculating Work of Expansion
Topic: -P vs P
Replies: 1
Views: 273

### -P vs P

Can someone explain further when and why the pressure for work of expansion is negative/postitive?
Tue Dec 01, 2015 9:16 pm
Forum: Polyprotic Acids & Bases
Topic: Problem 12.117
Replies: 1
Views: 345

### Problem 12.117

For this problem we're supposed to find the K of HNO_{2}+NH_{3}\rightarrow NH_{4}^{+}+NO_{2}^{-} . In the solution manual it sets K= \frac{[NH_{4}^{+}][NO_{2}^{-}]}{[HNO_{2}][NH_{3}]} = \frac{K_{a}(HNO_{2})K_{a}(NH_{3})}{K_{w}} . How do we know that the Ka of HNO2 multiplied by the K...
Tue Dec 01, 2015 8:47 pm
Forum: Polyprotic Acids & Bases
Topic: Finding Ka2 in problem 12.79
Replies: 1
Views: 413

### Finding Ka2 in problem 12.79

How do you find the value of ? It's in the solution manual, but I can't find it in the book.
Tue Dec 01, 2015 8:45 pm
Forum: Polyprotic Acids & Bases
Topic: HW # 12.79
Replies: 1
Views: 443

### Re: HW # 12.79

In the first reaction, H_{2}SO_{4} + H_{2}O\rightarrow HSO_{4}^{-} + H_{3}O^{+} , H_{2}SO_{4} goes through a complete ionization forming the hydronium ion H_{3}O^{+} and HSO_{4}^{-} , like a strong acid completely deprotonates. Because it goes through complete ionization we can assume that the initi...
Sun Nov 29, 2015 2:31 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Problem 12.39
Replies: 2
Views: 482

### Problem 12.39

For this problem you're supposed to use table 12.1 and 12.2 to place the four acids in order of increasing strengths, but only two of the values for two of the acids are in the tables. How can do you determine the other two values?
Fri Nov 20, 2015 10:54 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Increasing/Decreasing Pressure
Replies: 2
Views: 608

### Increasing/Decreasing Pressure

Can someone explain how increasing/decreasing the pressure will affect the equilibrium?
Thu Nov 19, 2015 2:30 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: The pOH of Solutions
Replies: 1
Views: 266

### Re: The pOH of Solutions

Since the equilibrium constant for autoprotolysis of water is K_{c}=\frac{[H_{3}O^{+}][OH^{-}]}{[H_{2}O]^{2}}=[H_{3}O^{+}][OH^{-}]=K_{W} which is equal to 1.0X10^-14, we can say that the H+ and OH- ions are inversely related since Kw is a constant. We can then take the -log of each side which can be...
Thu Nov 19, 2015 1:46 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 2013 Quiz 3 Preparation #10
Replies: 10
Views: 1266

### Re: 2013 Quiz 3 Preparation #10

So how would you determine what the value of x is? Is the new equilibrium for Br2 4.9-x and for Cl2 7.6-x?
Thu Nov 19, 2015 1:34 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligand Binding Sites
Replies: 1
Views: 407

### Ligand Binding Sites

How can you determine how many binding sites a ligand has?
Wed Oct 14, 2015 1:03 pm
Forum: Quantum Numbers and The H-Atom
Topic: Rydberg vs H-Atom Equation
Replies: 1
Views: 322

### Rydberg vs H-Atom Equation

I understand that the H-Atom equation only works with hydrogen atoms, but can I use the Rydberg equation for hydrogen as well? Is there any time that using the H-Atom equation makes more sense or would be easier/more accurate to use?
Mon Oct 05, 2015 11:20 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy