Search found 68 matches
Re: Final
So we would want to remember the 6 functional groups?
- Sat Mar 16, 2019 9:31 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Cv or Cp
- Replies: 5
- Views: 698
Cv or Cp
How do you know whether to use Cv=(3/2)*R or Cp=(5/2)*R?
- Wed Mar 13, 2019 12:21 am
- Forum: Second Order Reactions
- Topic: 2nd order rates
- Replies: 6
- Views: 832
2nd order rates
Just to clarify:
If a 2nd order rate looked like rate = k [OH-] [H3Br]
the rate is second order for the reaction
but the rate is first order for each reactant?
If a 2nd order rate looked like rate = k [OH-] [H3Br]
the rate is second order for the reaction
but the rate is first order for each reactant?
- Tue Mar 12, 2019 9:56 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Electrolysis
- Replies: 2
- Views: 835
Electrolysis
I'm confused as to what we need to know for electrolysis for the final?
- Sun Mar 10, 2019 11:24 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6L.3
- Replies: 1
- Views: 234
6L.3
In the 7th edition, 6L #3 part a it asks for the half reactions for problems like Ni(s) | Ni2+ (aq) || Ag+ (aq) | Ag (s) are the half reactions: Ag+ (aq) + e- --> Ag (s) E(cathode) = +0.80 V Ni2+ (aq) + 2e- --> Ni (s) E (anode) = -0.23 V OR ARE THE HALF REACTIONS (with the reversed anode half reacti...
- Sun Mar 10, 2019 11:03 pm
- Forum: Balancing Redox Reactions
- Topic: 6K.3 part d
- Replies: 2
- Views: 286
Re: 6K.3 part d
So you would set it up the half reactions like: Cl2 (g) --> HClO (aq) + Cl2 (g)
Cl2 + 2 H2O --> 2 HCLO(g) + 2H+
Cl2 --> Cl2 (g)??
Cl2 + 2 H2O --> 2 HCLO(g) + 2H+
Cl2 --> Cl2 (g)??
- Sun Mar 10, 2019 11:01 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Enot
- Replies: 2
- Views: 324
Re: Enot
E not is made up of state functions so therefore it is a state function
- Sun Mar 10, 2019 7:46 pm
- Forum: Balancing Redox Reactions
- Topic: 6K.3 part d
- Replies: 2
- Views: 286
6K.3 part d
In the 7th edition, 6K #3 asks that you balance the following redox rxn in an acidic solution and find the oxidizing/reducing agent. Part d had the equation) Cl2 (g) --> HClO (aq) + Cl2 (g) The answer is H2O (l) + Cl2 (g) --> HOCl (aq) + H+ (aq) + Cl- (aq) where Cl2 is both the oxidizing and reducin...
- Sun Mar 03, 2019 11:28 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Element's potentials
- Replies: 5
- Views: 638
Re: Element's potentials
Should we be using the periodic table reference in the text or the list of potentials in the textbook?
- Sun Mar 03, 2019 11:24 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Pt(s)
- Replies: 10
- Views: 1075
Re: Pt(s)
You need something for it to attach to (a solid). I'm not exactly sure why it has to be Pt though
- Sun Mar 03, 2019 11:23 pm
- Forum: Balancing Redox Reactions
- Topic: OH-
- Replies: 5
- Views: 581
OH-
how do you know when you need to add OH-
- Sun Feb 24, 2019 11:34 pm
- Forum: *Free Energy of Activation vs Activation Energy
- Topic: Spontaneous reactions
- Replies: 11
- Views: 4637
Re: Spontaneous reactions
You just want to make sure delta G is negative. So if the equation (ΔG=ΔH−TΔS) is manipulated in a way in which delta G is negative, it is spontaneous.
- Sun Feb 24, 2019 11:31 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test 2
- Replies: 9
- Views: 1130
Re: Test 2
Are the other parts of thermodynamics section going to be included?
- Sun Feb 24, 2019 11:30 pm
- Forum: Balancing Redox Reactions
- Topic: Work done
- Replies: 2
- Views: 308
Re: Work done
I thought when delta E was positive, system was gaining Energy?
- Sun Feb 17, 2019 11:10 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Ideal Gas C
- Replies: 5
- Views: 806
Re: Ideal Gas C
I think it has something to do with the fact that Cp= Cv+R. Since Cv=3/2 R that would mean Cp= 3/2R + R = 5/2R
- Sun Feb 17, 2019 11:07 pm
- Forum: Ideal Gases
- Topic: Calculating Pressure of a Gas Mixture Using PV=nRT
- Replies: 3
- Views: 575
Re: Calculating Pressure of a Gas Mixture Using PV=nRT
You can also solve for each one individually and then add them together
- Tue Feb 12, 2019 7:45 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Std Enthalpy of Formations
- Replies: 1
- Views: 210
Std Enthalpy of Formations
Why is it that molecules like O2 and N2 not included when trying to figure out enthalpy of a reaction...?
- Sun Feb 10, 2019 11:15 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 4C.3
- Replies: 1
- Views: 223
4C.3
In the 7th Ed. section 4c. #3 it asks that you find the final T and change in enthalphy when a) @ constant pressure and b) @ constant volume
I know when there is constant pressure the change in enthalpy, delta H= q
Is it the same for when there is constant volume?
delta H=q???
I know when there is constant pressure the change in enthalpy, delta H= q
Is it the same for when there is constant volume?
delta H=q???
- Sat Feb 09, 2019 11:52 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 4A.13
- Replies: 2
- Views: 285
Re: 4A.13
Thank you!
Do you think that this explanation makes sense: Since the reaction released the 3.5 kj, the calorimeter is getting the 3.50kj of work done on it.. So when work is done on the system (calorimeter), it is (+)?
Do you think that this explanation makes sense: Since the reaction released the 3.5 kj, the calorimeter is getting the 3.50kj of work done on it.. So when work is done on the system (calorimeter), it is (+)?
- Sat Feb 09, 2019 10:00 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Gas constant, R
- Replies: 3
- Views: 424
Gas constant, R
How do you know which Gas constant, R to use 8.206 e-2 L atm k-1 mol-1 or 8.314 e-2 J k-1 mol-1?
- Sat Feb 09, 2019 7:35 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: 4A.13
- Replies: 2
- Views: 285
4A.13
In the 7th Ed. Section 4A Q13, the problem states "a constant volume calorimeter was calibrated by carrying out a rxn known to release 3.5 kJ if heat in 0.2 L of sol. in the calorimeter (q=-3.50kJ). When calculating C, the solutions manual changed the q from -3.50 kj to + 3.50 kj...why?
- Sun Feb 03, 2019 11:22 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Heat VS. Energy
- Replies: 5
- Views: 7866
Re: Heat VS. Energy
heat=energy and enthalpy is the transfer of heat/energy
- Sun Feb 03, 2019 11:19 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Closed Systems
- Replies: 6
- Views: 509
Re: Closed Systems
What are some examples of both?
- Mon Jan 28, 2019 8:47 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: K versus C*
- Replies: 2
- Views: 241
K versus C*
In class, Lavelle used Kelvin and Celsius interchangeably when describing specific heat. How is it that that the heat required to raise the temperature of some ethanol is 49 kJ/C* or kJ/K?
- Sun Jan 27, 2019 7:48 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 5J.11 (b) 7th edition
- Replies: 2
- Views: 277
Re: 5J.11 (b) 7th edition
It can be helpful to view heat as a reactant since it is endothermic according to the explanation in the response above.
- Tue Jan 22, 2019 5:00 pm
- Forum: Ideal Gases
- Topic: ICE table
- Replies: 5
- Views: 760
Re: ICE table
If they give you barr and a volume that is not 1.0L is that volume significant? As in, do we need to change the barr by dividing it by volume?
- Mon Jan 21, 2019 10:41 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Stability
- Replies: 3
- Views: 283
Stability
What is the correlation between how small/big the equilibrium constant is in comparison to the stability?
- Sat Jan 19, 2019 1:15 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: temperature
- Replies: 2
- Views: 339
Re: temperature
In what cases would we need to manipulate the equation then when there is a temperature change?
- Sat Jan 19, 2019 1:13 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Explaining pressure increase in terms of concentration
- Replies: 2
- Views: 375
Re: Explaining pressure increase in terms of concentration
increasing pressure favors the side with fewer moles of gas, in this case it would be reactants
- Fri Jan 18, 2019 3:25 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Equations with Salt
- Replies: 2
- Views: 276
Re: Equations with Salt
The rule of thumb is that salts completely dissassociate
- Mon Jan 14, 2019 11:28 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Volume and Pressure
- Replies: 2
- Views: 242
Volume and Pressure
I understand that volume and pressure are inversely related, I'm still a little confused about how this correlates with favoring the side with more moles?
- Mon Jan 14, 2019 11:17 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Converting Kc to Kp
- Replies: 3
- Views: 644
Re: Converting Kc to Kp
I think we've learned how to find Kc and Kp (the way to do it for each is essentially the same) however we have not learned how to convert between the two. We know how to take pressure to concentration.
- Mon Jan 14, 2019 7:16 pm
- Forum: Ideal Gases
- Topic: Kc and Kp
- Replies: 6
- Views: 386
Re: Kc and Kp
Does 'K' most often refer to Kp or Kc?
- Sun Dec 09, 2018 7:49 pm
- Forum: Lewis Acids & Bases
- Topic: Na+
- Replies: 3
- Views: 868
Re: Na+
There's a table in the textbook that shows that Na+ is a neutral in acid/base rxns so in the net equation it is not included.
- Sat Dec 08, 2018 1:12 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Equilibria for weak acids/bases
- Replies: 1
- Views: 232
Equilibria for weak acids/bases
For weak acids/bases since they do not deionize completely, the arrow should be that of constant equilibria between reactants and products (one arrow for forward rxn and one arrow for backward rxn). However in the textbook (7th ed) in Fundamentals J question 17 a-d that asks for the chem eqn for the...
- Fri Dec 07, 2018 10:25 pm
- Forum: Hybridization
- Topic: Composition of a sigma bond with Hydrogen
- Replies: 1
- Views: 132
Composition of a sigma bond with Hydrogen
How would the composition of a sigma bond with a hydrogen be written. i.e. a single bond between H and C
Would it look something like sigma (C 2sp^3 , H s)?
Would it look something like sigma (C 2sp^3 , H s)?
- Tue Dec 04, 2018 12:18 am
- Forum: Naming
- Topic: Roman Numerals
- Replies: 2
- Views: 280
Re: Roman Numerals
so not necessary when we name them?
- Mon Dec 03, 2018 11:45 pm
- Forum: Naming
- Topic: Roman Numerals
- Replies: 2
- Views: 280
Roman Numerals
When naming complex ions, should we include the roman numerals indicating the charge of the acid. The solutions manual did not include roman numerals.
- Mon Dec 03, 2018 3:08 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemistry Community Submissions
- Replies: 2
- Views: 218
Re: Chemistry Community Submissions
Thank you! My name is not online publicly, is that still okay?
- Mon Dec 03, 2018 2:51 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemistry Community Submissions
- Replies: 2
- Views: 218
Chemistry Community Submissions
Is there some place we can check to make sure our chemistry community submissions have been going through every week?
- Sun Dec 02, 2018 6:35 pm
- Forum: Bronsted Acids & Bases
- Topic: Calculations Involving Strong Acid (or Base)
- Replies: 3
- Views: 235
Re: Calculations Involving Strong Acid (or Base)
Are you referring to the problems that take the pH and do calculations with that using log?
- Sun Dec 02, 2018 6:30 pm
- Forum: Naming
- Topic: Common ions
- Replies: 1
- Views: 110
Common ions
Are there common ions we should know when it comes to naming? and what are they?
Naming
What is the order when it comes to naming?
- Sun Nov 25, 2018 10:30 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3701431
Re: Post All Chemistry Jokes Here
What is the gender of Iron Man?
Fe Male
Fe Male
- Sun Nov 25, 2018 10:17 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3701431
Re: Post All Chemistry Jokes Here
once i told a chemistry joke...there was no reaction.
- Sun Nov 25, 2018 10:13 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3701431
Re: Post All Chemistry Jokes Here
If Avogadro calls tell him to leave his number
- Sun Nov 25, 2018 10:07 pm
- Forum: Hybridization
- Topic: Double Bonds
- Replies: 4
- Views: 480
Re: Double Bonds
So if double bonds are both sigma and pi bonds, is it in hybridized orbital or between pi orbitals?
- Sun Nov 25, 2018 9:54 pm
- Forum: Hybridization
- Topic: promoted hybridization
- Replies: 4
- Views: 446
Re: promoted hybridization
It is simply when an electron goes from a lower to higher energy level. Energy is released (negative).
- Sun Nov 25, 2018 9:53 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Nodal Planes
- Replies: 3
- Views: 336
Nodal Planes
What exactly is a nodal plane?
- Sun Nov 11, 2018 9:29 pm
- Forum: Octet Exceptions
- Topic: learning octet excptions
- Replies: 4
- Views: 385
Re: learning octet excptions
I would say the elements where the octet rule is strictly enforced is rows 1 & 2 (other than H/He) since rows 3 on have access to d orbital like the above response mentioned.
- Sun Nov 11, 2018 9:24 pm
- Forum: Electronegativity
- Topic: Electron Affinity
- Replies: 3
- Views: 916
Re: Electron Affinity
The more stable ion is K+ because it has a full shell, thus it is less likely to gain an electron.
- Sun Nov 11, 2018 9:22 pm
- Forum: Resonance Structures
- Topic: Drawing resonance structures
- Replies: 5
- Views: 759
Re: Drawing resonance structures
When they ask for the lewis structures, does that refer to all lowest energy resonance structures?
- Sun Nov 04, 2018 10:00 am
- Forum: Lewis Structures
- Topic: Drawing Lewis Structures
- Replies: 14
- Views: 2096
Re: Drawing Lewis Structures
I'm still confused about the arrangement about the atoms. For examples TB (7th ed) 2C.3c says to draw the lewis structure of HClO3 and I arranged the atoms of oxygen and hydrogen around Cl. The solution manual put the H connected to the Oxygen instead. How would I have known to do this?
- Sun Nov 04, 2018 9:50 am
- Forum: Lewis Structures
- Topic: Common Ions-Midterm [ENDORSED]
- Replies: 1
- Views: 180
Common Ions-Midterm [ENDORSED]
What are the common ions we should know as some of the homework questions do not give us formulas but the name i.e. Draw the Lewish Structure for Chloric Acid
- Sat Nov 03, 2018 10:21 pm
- Forum: Lewis Structures
- Topic: Complete Lewis Structures
- Replies: 1
- Views: 140
Complete Lewis Structures
Does anyone know the difference between lewis structures and complete lewis structures. (7th Edition TB 2B.9)
- Sun Oct 28, 2018 7:46 pm
- Forum: Ionic & Covalent Bonds
- Topic: Exceptions to Octet
- Replies: 2
- Views: 247
Re: Exceptions to Octet
H and He are in the 1s shell which only need 2 e- to be a full shell. Li and Be are metals who tend to lose electrons and become the "noble gas" configuration of He (1s shell).
- Sun Oct 28, 2018 7:41 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: hw problem 3.51 6th edition
- Replies: 2
- Views: 233
Re: hw problem 3.51 6th edition
Formal Charge = [# of valence electrons on atom] – [non-bonded electrons + number of bonds]
- Sun Oct 28, 2018 7:36 pm
- Forum: Ionic & Covalent Bonds
- Topic: bound atoms
- Replies: 8
- Views: 1252
Re: bound atoms
Bonded atoms are more stable than unbonded atoms. For example, in the covalent bond of H2, the electrons from the atoms get to be near 2 protons instead of only the one proton it had initially.
- Tue Oct 23, 2018 11:19 am
- Forum: Properties of Electrons
- Topic: Test question
- Replies: 6
- Views: 632
Re: Test question
Does anyone know what information will be given to us...in terms of formulas and what not. Do we need to know the mass of an electron?
- Sun Oct 21, 2018 1:32 pm
- Forum: Einstein Equation
- Topic: Units
- Replies: 17
- Views: 1786
Re: Units
1 joule = 1kg·m^2·s^-2
If you divide it by s-1. One of the 's' cancels out and you get 1kg·m^2·s^-1.
If you divide it by s-1. One of the 's' cancels out and you get 1kg·m^2·s^-1.
- Sun Oct 21, 2018 1:22 pm
- Forum: Trends in The Periodic Table
- Topic: Periodic Table Trends
- Replies: 5
- Views: 643
Re: Periodic Table Trends
ATOMIC RADIUS- increases down and to the left
IONIZATION ENERGY & ELECTRON AFFINITY-increases up and to the right
metals are on the left and nonmentals are on the right
IONIZATION ENERGY & ELECTRON AFFINITY-increases up and to the right
metals are on the left and nonmentals are on the right
- Sun Oct 21, 2018 1:18 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Where does this section end in the textbook? [ENDORSED]
- Replies: 2
- Views: 277
Re: Where does this section end in the textbook? [ENDORSED]
I'm pretty sure that its all the sections under "the quantum world" so 1a, 1b, 1d, 1e, 1f
- Sat Oct 13, 2018 9:03 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Negative v. Positive when calculating energy
- Replies: 8
- Views: 2527
Re: Negative v. Positive when calculating energy
Anytime energy is released it is considered negative.
- Sat Oct 13, 2018 8:52 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3701431
Re: Post All Chemistry Jokes Here
How often do I tell chemistry jokes? periodically.
- Sat Oct 13, 2018 8:48 pm
- Forum: Trends in The Periodic Table
- Topic: electron affinity [ENDORSED]
- Replies: 15
- Views: 2026
Re: electron affinity [ENDORSED]
As a side note, the general trend for electron affinity is that it increase upwards and from left to right of the periodic table.
- Sun Oct 07, 2018 9:01 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Avogadro's Constant Definition
- Replies: 7
- Views: 1063
Re: Avogadro's Constant Definition
I have a similar question. Sometimes questions ask for atoms of Cl2. Does this mean the individual atoms (6.02x10^23) or is it referring to the number of Cl2 atoms in a compound like ZnCl2 has 1 atom of Cl2?
- Sun Oct 07, 2018 7:28 pm
- Forum: Balancing Chemical Reactions
- Topic: H19
- Replies: 3
- Views: 383
Re: H19
Adding on to what Chathuri said, just because combustion reactions always produce CO2 and H2O, it does not mean it is limited to producing only those compounds. It means it must product those, but if there are other elements involved such as aspartame, N2 is also going to be produced separately.
- Sun Oct 07, 2018 7:09 pm
- Forum: Limiting Reactant Calculations
- Topic: G25
- Replies: 1
- Views: 205
G25
Does anyone understand G25? It is about doubling the volume of the solution 90 times.