## Search found 49 matches

Fri Mar 16, 2018 9:55 pm
Forum: Van't Hoff Equation
Topic: Ka vs K
Replies: 2
Views: 207

### Ka vs K

How is Ka different from K and how would we consider the difference when solving equations for the equilibrium constant?
Fri Mar 16, 2018 9:53 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: state functions
Replies: 4
Views: 423

### Re: state functions

The state functions are Enthalpy, Volume, Temperature, Pressure, Density, Heat Capacity, Energy, and Gibbs Free Energy. Work and heat are not state functions.
Fri Mar 16, 2018 9:51 pm
Forum: *Nucleophiles
Topic: nucleophile?
Replies: 4
Views: 515

### nucleophile?

What is a nucleophile?
Fri Mar 16, 2018 9:50 pm
Forum: *Alkanes
Topic: Final
Replies: 13
Views: 1262

### Re: Final

I think it would be sufficient to know the names and structure of each functional group and be able to distinguish between their pictures
Thu Mar 15, 2018 6:11 pm
Forum: Phase Changes & Related Calculations
Topic: 9.19
Replies: 1
Views: 191

### 9.19

For question 9.19, why do you have to do 3 steps when calculating change in entropy? Why does it make sense to decrease the temperature again after heating it and doing phase change?
Tue Mar 13, 2018 7:38 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: entropy in reversible/irreversible processes
Replies: 1
Views: 212

### entropy in reversible/irreversible processes

If entropy is a state function and therefore the pathway to get to the end state does not matter, why are there different equations for entropy based on whether the pathway is reversible vs irreversible?
Wed Feb 28, 2018 7:31 pm
Forum: First Order Reactions
Topic: reaction order
Replies: 2
Views: 143

### reaction order

Do reaction orders always have to be whole numbers or can they also have fractional orders?
Wed Feb 28, 2018 7:29 pm
Forum: Zero Order Reactions
Topic: Negative order
Replies: 4
Views: 195

### Negative order

What does it mean for a reaction to have a negative order?
Sun Feb 25, 2018 2:23 pm
Forum: Zero Order Reactions
Topic: zero order slopes
Replies: 5
Views: 247

### zero order slopes

do zero order reactions have a constant slope, a slope of zero, or a varying slope throughout the entire reaction?
Sun Feb 25, 2018 2:20 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Rate constant (k)
Replies: 4
Views: 190

### Re: Rate constant (k)

K is constant for each different reaction since they each have different molecules reacting at different temperatures and thus would require a different constant value to carry out the reaction. However K is the same for each individual reaction.
Sun Feb 25, 2018 2:16 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Initial rates
Replies: 5
Views: 254

### Re: Initial rates

The curve of the concentration vs time graphs show that as the reaction proceeds, the curves level out... therefore, if you take the rate of the curve later on in the reaction, it will equal 0. This is when the reaction is in more of a thermodynamic setting rather than kinetic. Thus, we take the ini...
Sun Feb 18, 2018 10:37 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: system vs surroundings
Replies: 6
Views: 375

### Re: system vs surroundings

Just remember that the system + surroundings = universe. So whatever you label as your system, the rest will be surroundings.
Sun Feb 18, 2018 10:36 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic cells
Replies: 2
Views: 108

### Galvanic cells

Would a galvanic cell ever have more than one cathode/anode ?
Sun Feb 18, 2018 10:35 pm
Forum: Balancing Redox Reactions
Topic: "Rules"
Replies: 7
Views: 303

### Re: "Rules"

If you forget to balance the reaction is there a way to find that you have made a mistake at the end? Is there something that indicates that your answer does not make sense?
Sun Feb 11, 2018 11:40 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: delta H
Replies: 4
Views: 168

### delta H

Why are exothermic reactions favored if exothermic involves forming bonds?
Thu Feb 08, 2018 1:10 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: 9.76
Replies: 2
Views: 159

### 9.76

For question 9.76, how can we tell how many possible orientations the cis and trans compounds can have? Will we be required to evaluate this for the midterm?
Wed Feb 07, 2018 11:25 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 9.55
Replies: 1
Views: 134

### 9.55

On question 9.55 they ask us to calculate the change in Gibbs Free energy. We are able to find the change in entropy and change in enthalpy using the standard enthalpy of formations and standard molar entropies. However, the answer uses the temperature at 298 K... how are we able to assume this temp...
Sun Feb 04, 2018 9:53 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Measuring delta G
Replies: 4
Views: 182

### Measuring delta G

Is there any way to measure delta G? Or is the only way to calculate it using enthalpy and entropy?
Sun Feb 04, 2018 9:51 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: maximum G
Replies: 3
Views: 162

### maximum G

When G is a maximum why can the system no longer change?
Sun Feb 04, 2018 9:09 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: positional residual entropy
Replies: 4
Views: 169

### positional residual entropy

How is positional residual entropy different from regular entropy? Would this affect any calculations?
Sun Jan 28, 2018 4:26 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: W as a maximum
Replies: 3
Views: 162

### Re: W as a maximum

To add on to this idea:
Since the W is a maximum for the isolated system at equilibrium, entropy is also a maximum at equilibrium.
Sun Jan 28, 2018 4:23 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: The second law ?
Replies: 3
Views: 138

### Re: The second law ?

If you only consider the first law, you will only be considering the change in enthalpy of the system. However, the change in entropy also is needed to describe the likelihood that the system will be in a particular state. This leads to the second law of thermodynamics which incorporates the effects...
Sun Jan 28, 2018 4:13 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: gas with 2x positions
Replies: 2
Views: 163

### gas with 2x positions

Why does each gas molecule have 2x positions available to it and therefore resulting in W2/W1=2 ?
Sat Jan 20, 2018 11:05 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: standard enthalpy of formation [ENDORSED]
Replies: 4
Views: 212

### Re: standard enthalpy of formation[ENDORSED]

Also,
the standard enthalpy of formation of an element in its most stable form is zero.
This could be used to help distinguish between the two.
Mon Jan 15, 2018 5:29 pm
Forum: Phase Changes & Related Calculations
Topic: reversible, isothermal expansion of a gas
Replies: 2
Views: 133

### reversible, isothermal expansion of a gas

Do we need to know how to do the problems (like in the green box on pg. 265 of the textbook) involving using the derivative to calculate the work of reversible, isothermal expansion of a gas?
Mon Jan 15, 2018 5:26 pm
Forum: Phase Changes & Related Calculations
Topic: work, heat, and internal energy
Replies: 2
Views: 150

### work, heat, and internal energy

The change in internal energy is the sum of work and heat. Both work and heat are not state functions, however internal energy is a state function. Why does adding together 2 not state functions produce a state function?
Sun Jan 14, 2018 11:45 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: State Property
Replies: 3
Views: 189

### Re: State Property

State properties include enthalpy, volume, temperature, pressure, density, heat capacity, and energy.
Sun Jan 14, 2018 11:41 pm
Forum: Calculating Work of Expansion
Topic: Constant External Pressure
Replies: 2
Views: 149

### Re: Constant External Pressure

Also, why does this pressure have to be constant? What will happen if it varies?
Sun Jan 14, 2018 11:33 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: work vs heat
Replies: 4
Views: 175

### work vs heat

There are two equations : Delta U = work(w) and Delta U = heat(q)
Does this mean both work and heat equal each other as well?
Sat Dec 09, 2017 9:28 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Strength of an acid
Replies: 14
Views: 619

### Strength of an acid

How does electronegativity affect the relative strength of an acid?
Sat Dec 09, 2017 9:04 pm
Forum: Photoelectric Effect
Topic: Number of photons and intensity
Replies: 2
Views: 156

### Number of photons and intensity

Does increasing the number of photons of light shone on a metal result in an increase in the intensity/amplitude of light?
Fri Dec 08, 2017 11:35 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands sharing electrons
Replies: 1
Views: 162

### Ligands sharing electrons

In a coordination complex, does the Ligand provide both electrons to the Lewis Base? Or do they share the two electrons from each atom?
Fri Dec 01, 2017 9:27 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Resonance and Polydentates
Replies: 1
Views: 158

### Resonance and Polydentates

Does a resonance structure have any effect on how many atoms can be involved in that polydentate?
Fri Dec 01, 2017 9:25 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Double bonds and poldentates
Replies: 1
Views: 162

### Double bonds and poldentates

If a coordination compound has a double bond on an atom, can that atom be involved in a polydentate?
Tue Nov 21, 2017 9:08 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Homework 17.35
Replies: 1
Views: 113

### Homework 17.35

Why is only B a chelating complex? All the structures seem like the central atom is being coordinated.
Tue Nov 21, 2017 8:56 pm
Forum: Naming
Topic: Naming
Replies: 1
Views: 114

### Naming

Do we have to know all the rules for naming coordination compounds for the test?
Tue Nov 21, 2017 8:55 pm
Forum: Naming
Topic: Naming
Replies: 1
Views: 95

### Naming

Do we have to know all the rules for naming coordination compounds for the test?
Tue Nov 07, 2017 8:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Midterm
Replies: 2
Views: 236

### Midterm

Will we have to draw Lewis structures for the midterm?
Tue Nov 07, 2017 8:48 pm
Forum: Resonance Structures
Topic: Lewis structure of SO3
Replies: 1
Views: 243

### Re: Lewis structure of SO3

That is correct. The one double bond can be drawn on any one of the three bonds between S and O. All the bonds have a bond length size in between the size of a single and double bond. However, this cannot be drawn on a VSEPR drawing and therefore a double bond is shown on one of the three bonds, ind...
Fri Nov 03, 2017 5:06 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape and Structure
Replies: 1
Views: 138

### Molecular Shape and Structure

Why does the atom with the lower ionization energy go in the center when drawing VSEPR models?
Fri Nov 03, 2017 4:55 pm
Forum: Resonance Structures
Topic: Question 3.69
Replies: 1
Views: 154

### Re: Question 3.69

The structure with a formal charges zero is more stable. For example, in the example we did in class of the SO4 molecule, the second drawing we did consists of the central atom with a formal charge of 0, making that drawing more stable than the first drawing which had the central atom of a formal ch...
Thu Oct 26, 2017 7:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Periodic Trends
Replies: 2
Views: 112

### Periodic Trends

In class we looked at the trends in ionization energy for atoms in the gaseous phase. How does this trend affect the atoms in other states, like liquid and solid?
Thu Oct 26, 2017 6:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar and Nonpolar
Replies: 3
Views: 344

### Re: Polar and Nonpolar

For example, the molecule CH4 is a non polar molecule since Carbon and Hydrogen have similar electronegativities. Alternatively, H2O is a polar molecule since oxygen has a higher electronegativity than hydrogen so oxygen pulls the electrons more closely to itself, making oxygen have a partial negati...
Wed Oct 18, 2017 8:46 pm
Forum: Properties of Light
Topic: EM spectrum
Replies: 6
Views: 421

### EM spectrum

Would we need to know all the wavelengths of light in the EM spectrum?
Wed Oct 18, 2017 8:31 pm
Forum: DeBroglie Equation
Topic: De Broglie's and Photoelectric Effect
Replies: 2
Views: 190

### De Broglie's and Photoelectric Effect

In question 1.33 how would you differentiate between using the kinetic energy formula and De Broglie's equation?
Thu Oct 12, 2017 10:26 pm
Forum: Properties of Light
Topic: converting units ( keV )
Replies: 2
Views: 209

### converting units ( keV )

In chapter 1 #23 the question gives the energy in the units of keV. How would we convert this to joules in order to use the energy to find wavelength?
Thu Oct 12, 2017 10:19 pm
Forum: Properties of Light
Topic: Lyman/Balmer/Paschen/Brackett series
Replies: 1
Views: 193

### Lyman/Balmer/Paschen/Brackett series

In question #11 in chapter 1, the answer states that the quantum number for the lower energy is the same for each absorption line however it gives the principal n number different for each series. Why is each principle number different and how does it affect each series grouping?
Thu Oct 05, 2017 6:26 pm
Forum: Balancing Chemical Reactions
Topic: Percent yield [ENDORSED]
Replies: 6
Views: 546

### Percent yield[ENDORSED]

For M1 the question asks what is the percent yield of hydrazine? The question gives the net ionic equation for the reaction. I was wondering if the net ionic equation plays a role in this problem since some of the dissolved ions are not written.
Thu Oct 05, 2017 6:20 pm
Forum: Limiting Reactant Calculations
Topic: M.9
Replies: 4
Views: 447

### Re: M.9

No we would not need to know the net ionic equation for this test. However we do need to know how to balance the chemical equation. In this case the balanced equation would be Cu(NO3)2 + 2NaOH --> Cu(OH)2 + 2NaNO3. You would set up the net ionic equation by determining if the molecules are soluble o...