## Search found 61 matches

Sun Mar 17, 2019 2:10 am
Forum: Biological Examples
Topic: biological examples for final
Replies: 9
Views: 596

### Re: biological examples for final

i am struggling to find examples as well
Sun Mar 17, 2019 2:07 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Final
Replies: 2
Views: 379

### Re: Final

i don't think we'll be asked to find change in internal temperature without being given information regarding the temperature
Sun Mar 17, 2019 2:06 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Delta S?
Replies: 2
Views: 366

### Re: Delta S?

for irreversible expansion, that means that the reaction occurs in an isolated system so neither energy nor matter can be exchanged between system and surroundings. therefore S of system = S of surroundings; so delta (change in) S = 0
Sun Mar 17, 2019 2:02 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Exothermic vs. Endothermic
Replies: 10
Views: 491

### Re: Exothermic vs. Endothermic

a reaction is endothermic is the E(a) (activation energy) of the forward reaction is higher than the reverse reaction. therefore, if the temperature increases, the rate constant of the forward reaction will increase because k is dependent on temperature.
Sun Mar 17, 2019 1:12 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Test 2 Question 5
Replies: 5
Views: 516

### Re: Test 2 Question 5

what do you use a k1 value ? how do you calculate k2 when we're only given kw ?
Sat Mar 16, 2019 12:00 am
Forum: *Enzyme Kinetics
Topic: what will we be given ?
Replies: 3
Views: 383

### what will we be given ?

will we be given the E(a) of a reaction, or do we have to solve for it ?
Fri Mar 15, 2019 11:59 pm
Forum: *Enzyme Kinetics
Topic: How do you tell if something is a catalyst vs an intermediate?
Replies: 16
Views: 1072

### Re: How do you tell if something is a catalyst vs an intermediate?

so intermediates are always found as a product in the first reaction and reactant in the second ? and vice versa for enzymes ?
Fri Mar 15, 2019 11:57 pm
Forum: *Enzyme Kinetics
Topic: final
Replies: 2
Views: 380

### final

to what extent do we need to know enzyme kinetics for the final ?
Fri Mar 15, 2019 11:57 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Exothermic vs Endothermic
Replies: 6
Views: 267

### Re: Exothermic vs Endothermic

so to clarify, if a higher activation energy is needed for the forward reaction compared to the reverse reaction, then the reaction is endothermic ?
Fri Mar 15, 2019 11:55 pm
Forum: Zero Order Reactions
Topic: writing rate
Replies: 2
Views: 300

### writing rate

does it matter whether we write "rate" or d(A)/d(t) ?
Fri Mar 15, 2019 10:50 am
Forum: Second Order Reactions
Topic: units of K
Replies: 3
Views: 362

### units of K

what are the units of k for a second order reaction ?
Thu Mar 14, 2019 11:18 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: observed / experimental reaction mechanism
Replies: 1
Views: 79

### observed / experimental reaction mechanism

why do the experimental rate law and the one found by reaction mechanism sometimes not match - what do you do next ?
Thu Mar 14, 2019 11:16 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: pseudo rate law
Replies: 7
Views: 509

### pseudo rate law

can someone please explain pseudo rate law and why it's important
Thu Mar 14, 2019 11:14 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: calculating A in Arrhenius equation
Replies: 2
Views: 126

### calculating A in Arrhenius equation

how do we calculate A in the Arrhenius equation - I understand that it's the frequency of collision but how do we know what that number is ?
Thu Mar 14, 2019 11:13 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: catalyst or intermediate
Replies: 3
Views: 134

### catalyst or intermediate

how can we tell whether a compound is an intermediate or a catalyst ?
Thu Mar 14, 2019 11:12 pm
Forum: General Rate Laws
Topic: slow/fast steps
Replies: 7
Views: 198

### Re: slow/fast steps

My TA also said we would be told which reaction is slow and which is fast.
Thu Feb 28, 2019 5:25 pm
Forum: Balancing Redox Reactions
Topic: Acidic Solutions
Replies: 7
Views: 365

### Re: Acidic Solutions

When a molecule consists of an oxygen atom/s and changes (becomes product / or is reversed into reactant) into its elemental form (i.e. MnO4- becomes Mn2+), you must accommodate for the missing oxygen atom/s. Therefore, when the reaction occurs in an acidic solution, you add H2O to the side without ...
Thu Feb 28, 2019 5:19 pm
Forum: Balancing Redox Reactions
Topic: Writing half reactions
Replies: 7
Views: 256

### Re: Writing half reactions

When a molecule consists of an oxygen atom/s and changes (becomes product / or is reversed into reactant) into its elemental form (i.e. MnO4- becomes Mn2+), you must accommodate for the missing oxygen atom/s. Therefore, when the reaction occurs in an acidic solution, you add H2O to the side without ...
Thu Feb 28, 2019 5:11 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Finding n for the equation ΔG⁰=-nFE⁰
Replies: 8
Views: 331

### Re: Finding n for the equation ΔG⁰=-nFE⁰

to find the number of electrons transferred for the Gibbs Free energy equation, you have to split the reaction into its reduction and oxidation half reactions, then balance them to have equal number of electrons transferred in opposite directions. When the number of electrons transferred is the same...
Thu Feb 28, 2019 5:07 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: writing electrodes into cell diagrams
Replies: 1
Views: 73

### Re: writing electrodes into cell diagrams

You add Pt(s) to a cell diagram when one of the half reactions does not have an elements in solid form. For instance if the cell diagram is: Ag(s) I Ag+(aq) II H+(aq) I H2(g) neither of the elements on the right side are in solid form, therefore, you need to add Pt(s). so your correct cell diagram w...
Thu Feb 28, 2019 4:59 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cathode and Anode
Replies: 1
Views: 91

### Re: Cathode and Anode

Traditionally, the anode is on the left and the cathode is on the right because it indicates that the flow of electron is from right to left (because anode is losing electrons and cathode is gaining electrons). However, if you change the position of the anode and cathode, the flow of electron will b...
Tue Feb 26, 2019 12:55 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: salt bridge
Replies: 5
Views: 293

### Re: salt bridge

prevents the creation of a charge in either the anode or cathode by allowing ions to travel and keep the solutions neutral
Tue Feb 26, 2019 12:54 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Redox couples
Replies: 3
Views: 144

### Re: Redox couples

the reducing agent is the one that loses an electron during the reaction. the oxidizing agent is the one that gains an electron.
so if Fe2+ --> Fe3+, then it loses an electron because it becomes more positive, so it would be the reducing agent.
Tue Feb 26, 2019 12:50 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: test 2
Replies: 6
Views: 191

### test 2

how much about galvanic cells and their diagrams do we have to know for test 2 ?
Tue Feb 26, 2019 12:48 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Charges and coefficients?
Replies: 2
Views: 104

### Re: Charges and coefficients?

yes 2 Cl- ions will produce an overall -2 charge of that molecule
Tue Feb 26, 2019 12:45 pm
Forum: Van't Hoff Equation
Topic: solving van't hoff equation
Replies: 1
Views: 286

### solving van't hoff equation

what must remain constant in order to use the van't hoff equation ?
Tue Feb 26, 2019 12:44 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff Equation
Replies: 3
Views: 408

### Re: Van't Hoff Equation

what do you mean calculate K at a different temperature ?
Tue Feb 26, 2019 12:42 pm
Forum: Van't Hoff Equation
Topic: Van't Hoff Equation
Replies: 2
Views: 367

### Re: Van't Hoff Equation

yes, we will be tested on the van't hoff equation on test 2 - likely asked to solve for K using equation.
Tue Feb 26, 2019 12:40 pm
Forum: Van't Hoff Equation
Topic: van't hoff equation clarification
Replies: 2
Views: 356

### van't hoff equation clarification

to clarify, the van't hoff equation can be used to solve for the equilibrium constant of the reaction (K) ?
Tue Feb 26, 2019 12:35 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: delta Sm versus delta Sf [ENDORSED]
Replies: 1
Views: 261

### delta Sm versus delta Sf[ENDORSED]

Why are delta S(m) and delta S(f) different values for the same reaction ? In other words, why does the molar change in entropy differ from the change in entropy of formation ?
Tue Feb 26, 2019 11:15 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: exothermic reactions are spontaneous reactions
Replies: 1
Views: 91

### exothermic reactions are spontaneous reactions

in the 6th edition book, 9.51 asks why are so many exothermic reactions spontaneous ? I don't understand the answer given in the solutions manual and was wondering if anyone could clarify
Sun Dec 09, 2018 3:58 am
Forum: Identifying Acidic & Basic Salts
Topic: salts?
Replies: 1
Views: 257

### Re: salts?

salts form when an acid and a base have a neutralization reaction. Salts of weak bases produce acidic solutions and salts of weak acids produce basic solutions.
Sun Dec 09, 2018 3:55 am
Forum: Naming
Topic: -ate in naming
Replies: 7
Views: 597

### -ate in naming

when do you add -ate to the end of a compound's name ?
Sun Dec 09, 2018 3:53 am
Forum: Naming
Topic: CN Charge
Replies: 4
Views: 371

### Re: CN Charge

CN (cyanide) always has a -1 charge.
Sun Dec 09, 2018 3:52 am
Forum: Naming
Topic: Order of ligands
Replies: 6
Views: 504

### Re: Order of ligands

ligands are arranged in alphabetical order when written, but you ignore their prefixes! Therefore diaqua would not be written before pentaammine.
Sun Dec 09, 2018 3:50 am
Forum: Naming
Topic: Chloro vs Chlorito
Replies: 10
Views: 586

### Re: Chloro vs Chlorito

If a chloride ion is present, you change the -ide ending to chlorido. Typically chloro is not used to refer to a Cl- ion in a compound.
Sun Dec 09, 2018 3:45 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Abbreviations
Replies: 1
Views: 304

### Abbreviations

Do we need to know the abbreviates like (ox) or (en) for the test or will the formulas be given ?
Sun Dec 09, 2018 3:44 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Difference between Tetrahedral and Square Planar
Replies: 2
Views: 682

### Re: Difference between Tetrahedral and Square Planar

what is a d8 configuration and why does that matter regarding molecular shape ?
Sun Dec 09, 2018 3:42 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Lone pairs and polydentate [ENDORSED]
Replies: 1
Views: 334

### Lone pairs and polydentate[ENDORSED]

if a compound has one lone pair is it monodentate or you count the bound it already has in the compound and identify it as bidentate ?
Sun Dec 09, 2018 3:40 am
Forum: Identifying Acidic & Basic Salts
Topic: Which salts produce which solutions
Replies: 1
Views: 266

### Which salts produce which solutions

Why do salts of weak bases produce acidic solutions and salts of weak acids produce basic solutions?
Sun Dec 09, 2018 3:16 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligand order
Replies: 1
Views: 111

### Ligand order

how are ligands ordered in a compound ?
Sun Dec 09, 2018 2:45 am
Forum: Lewis Acids & Bases
Topic: Al as a Lewis Acid
Replies: 2
Views: 321

### Al as a Lewis Acid

I know in class we went over why Al in AlCl3 is a Lewis acid, but I cannot remember why it is an electron receptor and why group 13 elements are Lewis acids. I know they tend to not often have a full octet but how does that make them a Lewis acid ?
Sat Dec 08, 2018 3:05 pm
Forum: Bronsted Acids & Bases
Topic: Test topic
Replies: 1
Views: 89

### Test topic

In the homework problems, we are repeatedly asked to provide the name of a random acid. Will we have to be able to do this on the final ?
Sat Dec 08, 2018 3:03 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted base, Lewis acid
Replies: 2
Views: 104

### Re: Bronsted base, Lewis acid

All Lewis acids/bases are Bronsted acids/bases, but not all Bronsted acids/bases are Lewis acids/bases.
Fri Dec 07, 2018 6:32 pm
Forum: Sigma & Pi Bonds
Topic: Rotation
Replies: 5
Views: 503

### Re: Rotation

Sigma bonds do not fixate the atoms in one position because they only bind the two atoms' s orbitals. Pi bonds however, form between the p-orbitals of two atoms and secure the top and bottom of an atom in place. Therefore, the single atom is no longer able to rotate, but must move with the other ato...
Fri Dec 07, 2018 6:30 pm
Forum: Dipole Moments
Topic: Dipole dipole moments
Replies: 3
Views: 400

### Dipole dipole moments

does methane, CH4, have a dipole dipole interaction?
Fri Dec 07, 2018 6:12 pm
Forum: Amphoteric Compounds
Topic: What makes something amphoteric?
Replies: 6
Views: 519

### Re: What makes something amphoteric?

amphoteric substances react with both acids and bases.
i.e. Al2O3
Al2O3 + 6HCl --> 2AlCl3 + 3H20
in this reaction, aluminum chloride reacts with an acid, HCl

2NaOH + Al2O3 + 3H2O --> 2Na[Al(OH)4]
in this reaction, aluminum chloride reacts with a base, NaOH
Fri Dec 07, 2018 5:59 pm
Forum: Conjugate Acids & Bases
Topic: Chemical Equations
Replies: 6
Views: 453

### Re: Chemical Equations

To identify the conjugate base, you remove an H+ from the acid. To find the conjugate acid, you add an H+ to the base.
Fri Dec 07, 2018 5:56 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Strength of acid
Replies: 4
Views: 265

### Strength of acid

Why is it that when comparing strength of an acid (acidity) that the lower the element is in a group, the more acidic it is in a compound ?
Tue Dec 04, 2018 3:22 pm
Forum: Lewis Acids & Bases
Topic: Textbook section on acids
Replies: 3
Views: 188

### Textbook section on acids

Is the only part of the textbook that explains the basics of acids 17.5-17.6 ?? I'm confused on where to find more beginning material about acids and bases.
Sun Nov 25, 2018 9:44 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: electron-deficient compounds
Replies: 1
Views: 127

### electron-deficient compounds

what are electron-deficient compounds and have we gone over these in lecture ?
Sun Nov 25, 2018 9:41 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: bonding vs anti bonding orbitals
Replies: 2
Views: 211

### Re: bonding vs anti bonding orbitals

will this concept be on test #3 ?
Sun Nov 25, 2018 9:41 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Lone Pairs
Replies: 5
Views: 489

### Re: Lone Pairs

lone pairs on a central atom has exceptional repulsion strength so they try to repel all nearby bonds/electrons which is why some molecules with a lone pair on the central atom that should have a certain bond angle, have slightly different ones; the lone pair pushes the bonded pairs closer to one an...
Sun Nov 25, 2018 9:37 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: test #3
Replies: 14
Views: 758

### test #3

according to the website, it says all of molecular shape and bonding will be on test #3 but we haven't covered bond order, diamagnetism, or paramagnetism. so will these subjects be on test #3 or not ?
Sun Nov 25, 2018 9:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sigma and Pi Bonding
Replies: 2
Views: 57

### Sigma and Pi Bonding

Could anyone explain sigma and pi bonding because the way the textbook explains it is very confusing. I don't understand how to distinguish which bonds have a sigma bond and which have a pi bond and what nodal planes have to do with either.
Mon Nov 12, 2018 1:28 pm
Forum: Electronegativity
Topic: Ionic Character
Replies: 2
Views: 76

### Ionic Character

For exercise 3.77 in 6th edition, CO2 has more ionic character than CS2. Why does CO2 have more ionic character ? I know Sulfur is below C but why does that mean it has less of a difference in electronegativity with C than O does ? C and O are in the same row and wouldn't that make them more similar...
Sun Nov 11, 2018 6:31 pm
Forum: Ionic & Covalent Bonds
Topic: hydrogen bonds and melting points
Replies: 3
Views: 108

### hydrogen bonds and melting points

why does H2O have a higher melting point than H2S when H2S is covalently bonded ? covalent bonds are stronger than hydrogen bonds and therefore, would need more energy to break, but H2O has a higher melting point.
Sun Nov 11, 2018 6:23 pm
Forum: Electronegativity
Topic: Electronegativity and Noble Gases
Replies: 3
Views: 76

### Electronegativity and Noble Gases

Do noble gases have an electronegativity value of zero, or is it just a very small value ? Additionally, would noble gases not be considered reactive ?
Sun Nov 11, 2018 6:21 pm
Forum: Dipole Moments
Topic: Induced-Dipole Induced-Dipole
Replies: 5
Views: 368

### Re: Induced-Dipole Induced-Dipole

So van-der waals forces work because of induced-dipole induced dipoles ? Do induced-dipole induced-dipole moments affect any other type of bonding or exclusively van-der waals ?
Sun Nov 11, 2018 6:18 pm
Forum: Dipole Moments
Topic: Hydrogen Bonds
Replies: 20
Views: 635

### Re: Hydrogen Bonds

Hydrogen bonds are comparatively weak. Covalent bonds are the strongest, then ionic, then hydrogen bonds.
covalent > ionic > hydrogen bonds
Sun Nov 11, 2018 6:15 pm
Forum: Ionic & Covalent Bonds
Topic: Partial Charges Question
Replies: 2
Views: 140

### Partial Charges Question

So the only factor that contributes to partial charges is difference in electronegativity correct ? And the partial charges then contribute to the bond being polar covalent ?