## Search found 18 matches

Tue Mar 12, 2019 4:14 pm
Forum: First Order Reactions
Topic: Rate law with 2 reactants
Replies: 3
Views: 171

### Re: Rate law with 2 reactants

one of the reactants is 0th order, so the rate only depends on the concentration of the other one. When you write the overall rate law, you only include the reactants with order>0.
Tue Mar 12, 2019 4:11 pm
Forum: General Rate Laws
Topic: second and zeroth order half life "not used"
Replies: 2
Views: 121

### Re: second and zeroth order half life "not used"

the half life changes for 2nd and 0th order reactions based on the concentration of reactants, where the half life of 1st order reactions stays the same no matter the concentration of reactants at time t, since it depends only on the concentration at time =0. For the 2nd order reaction, 1/2 life inc...
Tue Mar 12, 2019 4:03 pm
Forum: Zero Order Reactions
Topic: Reaction Rate
Replies: 10
Views: 576

### Re: Reaction Rate

i believe so, as long as it's all the same products and reactants
Sat Mar 09, 2019 12:10 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: differential rate law equation
Replies: 3
Views: 164

### Re: differential rate law equation

to find the rate constant, k
Tue Mar 05, 2019 3:11 pm
Forum: First Order Reactions
Replies: 3
Views: 99

because the rate of decay is directly proportional to the concentration of atoms
Tue Mar 05, 2019 3:08 pm
Forum: First Order Reactions
Topic: Rate constant and half life
Replies: 3
Views: 171

### Re: Rate constant and half life

the half life is the time it take for a reactant to lessen its concentration by 1/2. the faster (or higher) the rate of reaction, the less time it will take for the reactants to reach 1/2 of their original concentration.
Tue Feb 26, 2019 8:47 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Writing Balanced Equations for Galvanic Cells (14.11 part d sixth edition)
Replies: 3
Views: 125

### Re: Writing Balanced Equations for Galvanic Cells (14.11 part d sixth edition)

you have to make sure that you're writing the cathode as a reduction reaction, so the product should have less charge than the reactant
Tue Feb 26, 2019 8:46 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Equations to use
Replies: 2
Views: 104

### Re: Equations to use

it just depends on the information you're given in the problem
Tue Feb 26, 2019 8:42 am
Forum: Balancing Redox Reactions
Topic: Oxidation and Reduction
Replies: 1
Views: 68

### Re: Oxidation and Reduction

you look at the periodic table, similar to valence electrons, the group its in determines the charge
Tue Feb 19, 2019 3:37 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: irreversible v reversible
Replies: 4
Views: 405

### Re: irreversible v reversible

If it is a reversible process (and it goes back to the original state) the change in entropy is 0. Since it has returned to its original state, there is no overall change in entropy for reversible processes.
Tue Feb 19, 2019 3:34 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Test 2
Replies: 4
Views: 379

### Re: Test 2

I think it's mostly Gibbs free energy for the thermodynamics part but I'm not sure exactly what days that was taught.
Tue Feb 19, 2019 3:32 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Test 2
Replies: 2
Views: 108

### Re: Test 2

all of Gibbs free energy (some thermodynamics) and electrochemistry (which we haven't learned yet) up to the Nernst equation
Tue Feb 12, 2019 6:28 pm
Forum: Calculating Work of Expansion
Topic: Irreversible expansion
Replies: 1
Views: 129

### Re: Irreversible expansion

yes - by the end of the reaction the external pressure and internal pressure are equal for irreversible processes
Tue Feb 12, 2019 4:22 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpy and Resonance
Replies: 1
Views: 121

### Re: Bond Enthalpy and Resonance

the carbon-carbon bonds are kind of in-between double and single bonds because of resonance, but there a specific bond enthalpy (518 kJ/mol) for carbon with a single bond and a dashed line on top, that represents the resonance of 3 C-C and 3 C=C bonds.
Tue Feb 12, 2019 4:16 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: enthalpy and internal energy
Replies: 1
Views: 98

### Re: enthalpy and internal energy

internal energy is the kinetic energy of the particles in a system, enthalpy (heat released/absorbed) is the internal energy plus the (pressure * volume) of the system
Tue Feb 12, 2019 4:10 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: the relation b/t change in H and change in U
Replies: 1
Views: 117

### Re: the relation b/t change in H and change in U

when you calculate delta H you use delta U + P (deltaV). When delta U is negative and you add P*deltaV to it to get delta H, enthalpy becomes less negative than delta U.
Sat Feb 02, 2019 4:16 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: U:Internal Energy
Replies: 4
Views: 184

### Re: U:Internal Energy

They are basically the same, you just pick which one you use based on what information you are given in the question.
Sat Feb 02, 2019 4:02 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Current Place in Class
Replies: 3
Views: 165

### Re: Current Place in Class

Yes - we have finished thermochemistry but are just beginning thermodynamics.