Search found 51 matches
- Sun Mar 07, 2021 5:54 pm
- Forum: General Rate Laws
- Topic: Why are there negative orders
- Replies: 14
- Views: 654
Re: Why are there negative orders
Yes, this is because of equilibrium.
- Sun Mar 07, 2021 5:52 pm
- Forum: General Rate Laws
- Topic: Rate Constant
- Replies: 31
- Views: 1129
Re: Rate Constant
Yes, the rate constant can be changed by temperature.
- Sun Mar 07, 2021 5:35 pm
- Forum: Environment, Ozone, CFCs
- Topic: stoichiometric coefficients
- Replies: 19
- Views: 1410
Re: stoichiometric coefficients
Both ways are correct. It's whatever you prefer.
- Sun Mar 07, 2021 5:34 pm
- Forum: Environment, Ozone, CFCs
- Topic: Homogeneous Catalysts and Ozone
- Replies: 6
- Views: 1607
Re: Homogeneous Catalysts and Ozone
Oxygen atoms can recombine to form oxygen molecules and if a free oxygen atom collides with an oxygen molecule, it forms the ozone. In these reactions, the atoms act as catalysts.
- Sun Mar 07, 2021 5:10 pm
- Forum: *Free Energy of Activation vs Activation Energy
- Topic: Definition of Transition State
- Replies: 7
- Views: 1516
Re: Definition of Transition State
Transition state is the highest energy structure along the reaction coordinate between reactants and products for every step of a reaction mechanism.
- Sun Mar 07, 2021 5:02 pm
- Forum: *Free Energy of Activation vs Activation Energy
- Topic: Definition of Transition State
- Replies: 7
- Views: 1516
Re: Definition of Transition State
Transition state is the highest energy structure along the reaction coordinate between reactants and products for every step of a reaction mechanism.
- Sun Mar 07, 2021 4:57 pm
- Forum: *Electrophiles
- Topic: Halogens
- Replies: 9
- Views: 2336
Re: Halogens
I think halogens can be considered as either nucleophiles or electrophiles.
- Sun Mar 07, 2021 4:46 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: Functional Groups Overlapping
- Replies: 3
- Views: 2711
Re: Functional Groups Overlapping
No, it is not possible for functional groups to overlap.
- Sun Mar 07, 2021 4:43 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: K meaning
- Replies: 29
- Views: 2071
Re: K meaning
K is the Boltzmann constant which is approximately 1.380649×10^−23 J/K.
- Thu Mar 04, 2021 2:24 pm
- Forum: *Free Energy of Activation vs Activation Energy
- Topic: Temperature vs. activation energy
- Replies: 33
- Views: 2423
Re: Temperature vs. activation energy
An increase in temperature (T) causes more collisions. This increases the reaction rate which is why k increases when the temperature does.
- Sun Feb 28, 2021 8:17 am
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: pH
- Replies: 6
- Views: 395
Re: pH
A pH meter is used to calculate the concentration of H+ ions in a solution to determine if it is alkaline or acidic. You can find Q to calculate the concentration of H+ ions.
- Sun Feb 28, 2021 8:11 am
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: pH meter
- Replies: 11
- Views: 639
Re: pH meter
A pH meter is used to calculate the concentration of H+ ions in a solution to determine if it is alkaline or acidic.
- Sun Feb 28, 2021 8:04 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: What is Potential?
- Replies: 14
- Views: 568
Re: What is Potential?
The cell potential for cathodes and anodes can be referred to as the reduction potential because it relates to their ability to gain electrodes. When the cathode has more potential than the anode, it means that they gain more electrons. The potential for anodes is less because they become oxidized a...
- Sun Feb 28, 2021 7:36 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: anode / Cathode
- Replies: 9
- Views: 570
Re: anode / Cathode
The anode is where oxidation reaction happens and therefore is negatively charged. The cathode is where reduction reaction happens so it becomes more positively charged. I think the anode can be positive in different types of cells.
- Sun Feb 28, 2021 7:31 am
- Forum: Balancing Redox Reactions
- Topic: Determining which molecule is the oxidizing agent
- Replies: 49
- Views: 1753
Re: Determining which molecule is the oxidizing agent
The reactant being reduced is the oxidizing agent and the reactant being oxidized is the reducing agent.
- Thu Feb 18, 2021 9:59 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Perfect System
- Replies: 3
- Views: 203
Re: Perfect System
A system is a perfect system if no heat is lost.
- Thu Feb 18, 2021 9:58 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Bomb Calorimeter
- Replies: 14
- Views: 4525
Re: Bomb Calorimeter
A bomb calorimeter is a closed system because it allows heat to be exchanged. Therefore, it is a perfect system since no heat is being lost.
- Thu Feb 18, 2021 9:54 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Finding bond enthalpies
- Replies: 6
- Views: 417
Re: Finding bond enthalpies
We add reactants and products when obtaining bond enthalpies.
- Thu Feb 18, 2021 9:42 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Cv and Cp
- Replies: 14
- Views: 2305
Re: Cv and Cp
Cp=Cv+R
Cv=Cp-R
R=8.314 J/kgK
Cv=Cp-R
R=8.314 J/kgK
- Thu Feb 18, 2021 9:40 pm
- Forum: Phase Changes & Related Calculations
- Topic: Steam
- Replies: 33
- Views: 1791
Re: Steam
Steam holds and releases more heat energy than the liquid form of water and therefore, causes more severe burns.
- Thu Feb 18, 2021 9:36 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Kekule Structures
- Replies: 3
- Views: 271
Re: Kekule Structures
I'm pretty sure Kekule structures are Lewis structures. They show an inaccurate representation because they suggest both carbon-carbon double bonds and carbon-carbon single bonds (aka two different types of carbon-carbon bonds in benzene).
- Thu Feb 18, 2021 9:29 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Inert gas
- Replies: 25
- Views: 1518
Re: Inert gas
Inert gases do not affect the volume because they are not reactive.
- Thu Feb 18, 2021 9:27 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Solving for Cubic Equations
- Replies: 13
- Views: 1038
Re: Solving for Cubic Equations
The value of K must be 1.0x10^-4 or less in order for x to be negligible.
- Thu Feb 18, 2021 9:24 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Acids and Bases
- Replies: 15
- Views: 785
Re: Acids and Bases
Memorizing would be the best option.
Strong Acids:
HCl
HBr
HI
H2SO4
HNO3
HClO4
HClO3
(Tip: all strong acids start with letter "H")
Strong Bases:
LiOH
NaOH
KOH
RbOH
CsOH
Ca(OH)2
Sr(OH)2
Ba(OH)2
Strong Acids:
HCl
HBr
HI
H2SO4
HNO3
HClO4
HClO3
(Tip: all strong acids start with letter "H")
Strong Bases:
LiOH
NaOH
KOH
RbOH
CsOH
Ca(OH)2
Sr(OH)2
Ba(OH)2
- Thu Feb 18, 2021 9:19 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Telling Apart Weak Bases vs Weak Acids by their Formula
- Replies: 11
- Views: 783
Re: Telling Apart Weak Bases vs Weak Acids by their Formula
Knowing the strong acids and bases will help you find out which ones are weak.
Strong Acids:
HCl
HBr
HI
H2SO4
HNO3
HClO4
HClO3
Strong Bases:
LiOH
NaOH
KOH
RbOH
CsOH
Ca(OH)2
Sr(OH)2
Ba(OH)2
Strong Acids:
HCl
HBr
HI
H2SO4
HNO3
HClO4
HClO3
Strong Bases:
LiOH
NaOH
KOH
RbOH
CsOH
Ca(OH)2
Sr(OH)2
Ba(OH)2
- Thu Feb 18, 2021 9:10 pm
- Forum: Ideal Gases
- Topic: Temperature
- Replies: 99
- Views: 5696
Re: Temperature
Yes, we assume it is 25 degrees.
- Thu Feb 18, 2021 9:09 pm
- Forum: Ideal Gases
- Topic: Ideal Gas
- Replies: 10
- Views: 489
Re: Ideal Gas
It is the general gas equation which is:
PV = nRT
They don’t attract or repel each other, but their interaction would be an elastic collision.
PV = nRT
They don’t attract or repel each other, but their interaction would be an elastic collision.
- Thu Feb 18, 2021 9:04 pm
- Forum: Ideal Gases
- Topic: Units for K
- Replies: 29
- Views: 1118
Re: Units for K
There are no units for K because it cancels out. K is a ratio, so you are just left with a value.
- Thu Feb 18, 2021 8:55 pm
- Forum: Van't Hoff Equation
- Topic: Sapling #18
- Replies: 12
- Views: 635
Re: Sapling #18
Raise it to the power of e like you would do for logs.
- Thu Feb 18, 2021 8:44 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Hard/Soft Water
- Replies: 5
- Views: 485
Re: Hard/Soft Water
Unlike soft water, hard water contains more mineral such as Ca+ and Mg2.
- Thu Feb 18, 2021 8:42 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: -OH vs OH-
- Replies: 36
- Views: 1225
Re: -OH vs OH-
It doesn't matter, -OH and OH- are the same thing in his lectures.
- Thu Feb 18, 2021 8:33 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Calorimeter Constants
- Replies: 2
- Views: 119
Re: Calorimeter Constants
Yes, calorimeter constants are always positive.
- Thu Feb 18, 2021 8:29 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration Cells
- Replies: 4
- Views: 770
Re: Concentration Cells
Yes and Yes. The concentration of a cell can have a positive Ecell and a cell be both galvanic and a concentration cell.
- Thu Feb 18, 2021 8:26 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Water and voltage
- Replies: 9
- Views: 1336
Re: Water and voltage
Yes, water will affect the voltage of a cell because water concentration will change.
- Thu Feb 18, 2021 8:07 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: Units of W
- Replies: 16
- Views: 711
Re: Units of W
Degeneracy does not have any units assigned to it.
- Thu Feb 18, 2021 8:04 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Which R to use
- Replies: 42
- Views: 2860
Re: Which R to use
8.314 because your answer should be in Joules.
- Thu Feb 18, 2021 7:41 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Delta U and Delta H
- Replies: 12
- Views: 4369
Re: Delta U and Delta H
Delta H = the change in enthalpy
Delta U = the change in internal energy.
Delta Hvap =Delta Uvap + pDelta V
The moles of gas do not change so ΔH≈ΔE if Δngas=0.
Delta U = the change in internal energy.
Delta Hvap =Delta Uvap + pDelta V
The moles of gas do not change so ΔH≈ΔE if Δngas=0.
- Thu Feb 18, 2021 7:35 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: When q=w
- Replies: 9
- Views: 421
Re: When q=w
ΔU = q + w
q is equal to w when it is negative (-w)
This is when ΔU = 0
q is equal to w when it is negative (-w)
This is when ΔU = 0
- Thu Feb 18, 2021 7:27 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Difference between E and E^o
- Replies: 4
- Views: 757
Re: Difference between E and E^o
E^o cell is cell potential at standard state and it doesn't change based on concentration. E cell is not at standard conditions and changes.
- Thu Feb 18, 2021 7:22 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: confusion on using Cp and Cv
- Replies: 24
- Views: 1018
Re: confusion on using Cp and Cv
Cp is the heat capacity when pressure is constant and Cv is the heat capacity when volume is constant. They are used in the equation Cp=Cv+R.
- Thu Feb 18, 2021 7:19 pm
- Forum: Environment, Fossil Fuels, Alternative Fuels
- Topic: Concept of "Cold"
- Replies: 8
- Views: 2566
Re: Concept of "Cold"
Heat flows naturally from an object at a higher temperature to an object at a lower temperature. Adding ice will continue to lower the temperature of the liquid that's not surrounding the ice. Ice will lower the overall temperature of the coffee.
- Thu Feb 18, 2021 7:15 pm
- Forum: Calculating Work of Expansion
- Topic: textbook 4A.5
- Replies: 5
- Views: 253
Re: textbook 4A.5
You should be fine without doing any calculations to show this.
- Thu Feb 18, 2021 7:10 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: q and delta h relationship
- Replies: 3
- Views: 202
Re: q and delta h relationship
q= delta H when pressure is constant.
- Thu Feb 18, 2021 7:06 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Question 4 HW 3/4
- Replies: 2
- Views: 180
Re: Question 4 HW 3/4
The stronger the bond, the greater the amount of energy is takes to break the bond. The strength of the correlates with how stable it is.
- Thu Feb 18, 2021 7:03 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Solids and Liquids?
- Replies: 26
- Views: 1294
Re: Solids and Liquids?
Only gases would apply to this.
- Thu Feb 18, 2021 7:00 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Strong Acids/Bases
- Replies: 19
- Views: 1281
Re: Strong Acids/Bases
You should memorize that H2SO4, HI, HBr, HNO3, HCl, HClO3, HClO4 are the seven strong acids.
- Thu Feb 18, 2021 6:54 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: qrev
- Replies: 27
- Views: 1483
Re: qrev
qrev is for a reversible process (heat transferred reversibly). q is the transfer of energy
- Thu Feb 18, 2021 6:48 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Homework question 4B.13
- Replies: 5
- Views: 250
Re: Homework question 4B.13
I don’t think there’s an error in the manual. w=-nRTln(V2/V1) is the formula you should be using.
- Thu Feb 18, 2021 6:45 pm
- Forum: Phase Changes & Related Calculations
- Topic: Week 5/6 Sapling Question 7
- Replies: 5
- Views: 280
Re: Week 5/6 Sapling Question 7
The amount that was vaporized is represented by a positive number not a negative number.
- Thu Feb 18, 2021 6:42 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: is HClO3 weak or strong? [ENDORSED]
- Replies: 49
- Views: 3964
Re: is HClO3 weak or strong? [ENDORSED]
HClO3 is a strong acid
- Thu Feb 18, 2021 6:38 pm
- Forum: Ideal Gases
- Topic: Sapling week 3/4 #15
- Replies: 7
- Views: 484
Re: Sapling week 3/4 #15
Find the moles of Na2 by using moles of NaN3.