## Search found 21 matches

Sun Mar 13, 2016 12:04 am
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: 3
Views: 602

### Re: Residual Entropy

What exactly is the residual entropy of an element? More specifically, I'm still confused on why NO has a higher residual entropy than BF3?
Sat Mar 12, 2016 11:53 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Winter 2011 Final
Replies: 1
Views: 328

### Winter 2011 Final

For question 1B, could anyone explain why the change in number of moles in 2 when the equation is
CH4 + 2O2 -----> 2H20 + Co2
Sat Mar 12, 2016 2:11 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Winter 2008 Final
Replies: 1
Views: 307

### Winter 2008 Final

Could anyone explain how in question 4 from Winter 2008, the reaction is first order with respect to B?
Sat Mar 05, 2016 10:35 pm
Forum: Calculating Work of Expansion
Topic: Work formulas
Replies: 3
Views: 554

### Work formulas

Does the work of expansion for reversible and irreversible process differ in any way?
Wed Mar 02, 2016 12:55 am
Replies: 2
Views: 392

How do you determine the number of intermediates in an addition reaction of a hydrogen halide and an organic molecule? Is the Bromine ion considered an intermediate in the first step?
Sun Feb 21, 2016 8:25 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: A as pre-exponential factor
Replies: 2
Views: 477

### Re: A as pre-exponential factor

Yes, the value of A should always be given to you or is usually a constant for very small temperature change.
Sun Feb 14, 2016 10:14 pm
Forum: General Rate Laws
Topic: Rate Laws
Replies: 2
Views: 416

### Rate Laws

When do we need the integrated rate law as opposed to the differential rate law?
Mon Feb 08, 2016 11:02 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Half equations
Replies: 1
Views: 285

### Half equations

Often the cell reaction is given to you and you're asked to construct the two half equations. When one of the half equations you would construct from the elements in the reaction is not given in the list of standard potentials, what are you meant to use? This was incorporated into question 15 in the...
Sun Jan 31, 2016 4:36 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Calculating the number of microstates
Replies: 2
Views: 2517

### Re: Calculating the number of microstates

In terms of calculating the microstates, when would we use the formula KBln(W2/W1) as opposed to kBln(V2/V1) and also is W the value of microstates itself or is degeneracy a different concept?
Sun Jan 24, 2016 6:02 pm
Forum: Phase Changes & Related Calculations
Topic: Unrelated
Replies: 3
Views: 423

### Re: Unrelated

Evaporation and boiling are actually two different processes, in its essence. Evaporation of water from the surface can take place at any temperature whereas the phase change to vapor due to boiling can only take place at 100 degrees celsius.
Sun Jan 17, 2016 9:44 pm
Forum: Phase Changes & Related Calculations
Topic: State Properties
Replies: 4
Views: 536

### State Properties

Why is that heat is not a state property but temperature is a state property?
Sun Jan 10, 2016 10:51 pm
Forum: Phase Changes & Related Calculations
Topic: Reversible and Irreversible Processes
Replies: 4
Views: 629

### Re: Reversible and Irreversible Processes

Reversible processes are reactions in which the forward reaction as well as the backward reaction can take place. More importantly, the products formed can react with each other in order to reform the initial reactants.
Fri Dec 04, 2015 11:34 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Calculating pH
Replies: 1
Views: 371

### Calculating pH

In what way does the calculation of pH for a solution with a weak acid differ from calculating pH when there is a strong acid?
Fri Dec 04, 2015 4:26 pm
Forum: Calculating the pH of Salt Solutions
Topic: Making Approximations
Replies: 1
Views: 394

### Making Approximations

While doing a pH calculation for salt solutions, we were told that if your X value is less than 5% of the initial, its okay to approximate. However, the approximation would take place before you calculate the X value, particularly while cross multiplying. SO when can we determine if we can approxima...
Wed Dec 02, 2015 10:57 pm
Forum: Calculating the pH of Salt Solutions
Topic: 2010 Final Q7B neutralization reaction
Replies: 2
Views: 619

### Re: 2010 Final Q7B neutralization reaction

A neutralization reaction is when an acid and a base react to give water and a salt. The moles of the components named can be calculated by the experimental process of titration as long as the concentration of one of the components is known.
Wed Dec 02, 2015 10:50 pm
Forum: Identifying Acidic & Basic Salts
Topic: Salts in Reactions
Replies: 1
Views: 379

### Re: Salts in Reactions

Salts are in fact included in the reaction equation as long as they are aqueous and can split up into their ions.
Sat Nov 28, 2015 11:01 pm
Forum: Dipole Moments
Topic: Polarity of Molecules
Replies: 2
Views: 589

### Polarity of Molecules

After doing a few questions, I've been confused on the relation between electron pair geometry, lone pairs and the polarity of a molecule. The first step to determining polarity would be to find a non-symmetric electron pair geometry. However if the shape is symmetric and there is a lone pair involv...
Sun Nov 22, 2015 10:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Partial Pressures
Replies: 1
Views: 369

### Partial Pressures

When working on a chemical equilibrium problem with gases, is atm or bar the preferred unit for calculation?
Mon Nov 02, 2015 12:27 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Anti-bonding
Replies: 1
Views: 301

### Anti-bonding

What exactly do the anti-bonding orbitals signify in the MO theory? Are these orbitals always filled with electrons and how do you determine wether they are?
Mon Oct 19, 2015 2:21 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Electron Repulsion in regards to VSEPR
Replies: 1
Views: 355

### Re: Electron Repulsion in regards to VSEPR

You actually answered your own question because the VSEPR theory itself states that electron repulsion affects the molecular shape of an atom. Lone pair-lone pair repulsion is greater than bond pair-bond pair and this causes the bond angle to increase which in turn affects the bond orientation. In t...
Sat Oct 10, 2015 2:14 pm
Forum: Properties of Electrons
Topic: Ionization Energy
Replies: 1
Views: 392

### Re: Ionization Energy

You would never have to calculate the ionization energy of an atom because the value is a constant which is given in the problem. It's usually used to calculate other values.