## Search found 21 matches

Sun Dec 10, 2017 12:44 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Video Module: Calculate Reaction Quotient
Replies: 1
Views: 227

### Video Module: Calculate Reaction Quotient

Calculate the reaction quotient, QC, from the following equilibrium data collected in a 3.00 L sealed reaction vessel for the reaction: AsH3 (g) ⇌ As (s) + H2 (g) AsH3 = 5.55 x 10-4 mol, As = 3.31 x 10-3 mol, H2 = 1.23 x 10-3 mol. 2AsH3 = 2As + 3H2 The reason I can not solve for this equation is bec...
Sun Dec 03, 2017 11:34 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Chemical Equilibrium [ENDORSED]
Replies: 1
Views: 159

### Chemical Equilibrium[ENDORSED]

Consider the following reaction at 1200K, for which you know Kc=1.7x10^-3 your experimental setup is able to measure the equilibrium concentration of Br2 based on its color but you are unable to measure the concentration of Br directly if you measure at equilibrium [Br2] to be 1.02x10^-4 M calculate...
Sun Dec 03, 2017 11:22 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Chemical Equilibrium
Replies: 3
Views: 219

### Chemical Equilibrium

This is a problem from the video modules Chemcial Equilibrium Part 1B. The question is are solvents included in equilibrium constant expressions? But, what are solvents? Is this because solvents are usually liquids but I thought they could be also solids and gases.
Sun Nov 26, 2017 6:49 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework Help 11.59
Replies: 2
Views: 158

### Re: Homework Help 11.59

A reaction mixture is prepared by mixing 0.100 mol SO2, 0.200 mol NO2, 0.100 mol NO, and 0.150 mol SO3 in a 5.00-L reaction vessel. The reaction SO2(g) + NO2(g) ∆ NO(g) + SO3(g) is allowed to reach equilibrium at 460 C, when Kc 85.0. What is the equilibrium concentration of each substance? So first ...
Sun Nov 26, 2017 6:21 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Chemical Equilibrium
Replies: 1
Views: 138

### Chemical Equilibrium

Chapter 11 # 53 A reaction mixture that consisted of 0.400 mol H2 and 1.60 mol I2 was introduced into a 3.00-L ask and heated. At equilibrium, 60.0% of the hydrogen gas had reacted. What is the equilibrium constant K for the reaction H2(g) + I2(g) ∆ 2 HI(g) at this temperature? Okay so first, H2 = 0...
Thu Nov 16, 2017 12:24 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle
Replies: 7
Views: 310

### Bond Angle

For many of the problem in Chapter 4 you are asked to write the lewis structure, VSEPR formula, name the shape and predict the approximate bond angle. I know how to solve the first 3 parts but how would you solve for the bond angle? Because the lewis structure sometimes does not reflect the approxim...
Fri Nov 10, 2017 12:21 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Magnetic Quantum Number
Replies: 6
Views: 327

### Re: Magnetic Quantum Number

The Principal quantum n would usually be given to you for you to solve. To find l you subtract n-1 which could take on the values 0,1,2,3,4..... and remember that l is also the subshell in which 0=s, 1=p, 2=d, 3=f. The value of m sub l is what ever l is such as l=2 m sub l equal both the negative an...
Thu Nov 02, 2017 7:57 pm
Forum: Bond Lengths & Energies
Topic: Bond Length
Replies: 5
Views: 289

### Re: Bond Length

Question: How do we know if we should make a bond : single, double, or triple?
Would we try to achieve a formal charge of 0 and that is how we would know.
Thu Nov 02, 2017 7:53 pm
Forum: Bond Lengths & Energies
Topic: Ionic Character and Covalent Character
Replies: 2
Views: 232

### Ionic Character and Covalent Character

How do we calculate ionic and covalent character. Or is something that we are given in a problem or that we must memorize?
Thu Nov 02, 2017 7:48 pm
Forum: Resonance Structures
Topic: Lewis Structures: Resonance Hybrid
Replies: 2
Views: 203

### Lewis Structures: Resonance Hybrid

A Practice Problem from Chapter 3 # 71 Select from teach of the following pairs of lewis structures the one that is likely to make the dominant contribution to a resonance hybrid. Explain your selection. I did not include the lewis structures that are included but is this problem asking which of the...
Thu Oct 26, 2017 11:31 pm
Forum: Ionic & Covalent Bonds
Topic: Chemical Bonds Lewis Structure: Octet Rule Violation [ENDORSED]
Replies: 3
Views: 611

### Chemical Bonds Lewis Structure: Octet Rule Violation[ENDORSED]

In each of these compounds, an atom violates the octet rule. Identify the atom and explain the deviation from the octet rule: (a) BeCl2; (b) ClO2. It makes sense why Be does not follow the octet rule because it only has 4 electrons but why does ClO2 not follow the octet rule? But how did we get odd ...
Wed Oct 25, 2017 11:37 pm
Forum: Formal Charge and Oxidation Numbers
Topic: homework 3.23
Replies: 4
Views: 393

### Re: homework 3.23

But where do we get or how do we figure out what oxidation numbers chlorine can have. Or is it something we have to memorized because if I would know how to get that then I would be able to write the electron configuration.
Wed Oct 25, 2017 11:33 pm
Forum: Lewis Structures
Topic: Chemical Bonds Lewis Structures
Replies: 1
Views: 142

### Chemical Bonds Lewis Structures

Write the Lewis Structures of (a) CCl4; (b) COCl2; (c) ONF; (d) NF3 Professor Lavelle gave us guidelines to be able to draw the Lewis structures which are: -count valence e- for each atom. -choose atom with the lowest ionization energy as central atom. But does this not apply in certain conditions. ...
Thu Oct 19, 2017 8:46 pm
Forum: Properties of Light
Topic: How to use the Rydberg Formula? [ENDORSED]
Replies: 6
Views: 408

### Re: How to use the Rydberg Formula?[ENDORSED]

Potentially aren't there two formulas which are v=-R [1/n1^2 - 1/n2^2] and you could also use the equation that professor Lavelle went over in class in which we calculate n 1 and 2 separately and then subtract them. It all come to which preference you prefer the first equation requires less computat...
Thu Oct 19, 2017 8:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Quantum Mechanics
Replies: 1
Views: 117

### Quantum Mechanics

Write the subshell notation (3d, for instance) and the number of orbitals having the following quantum numbers: (a) n = 5, l = 2; (b) n =1, l =0; (c) n =6, l =3; (d) n =2, l =1. How would you derive the subshell notation? What does subshell notation even mean?
Thu Oct 19, 2017 7:59 pm
Forum: Properties of Light
Topic: Photoelectric Effect Module Question
Replies: 2
Views: 221

### Re: Photoelectric Effect Module Question

It's me again the one that asked the question. I have an example that I think relates because it ask for the energy but the equation used can find you the frequency if you were given the energy Calculate the energy per photon of ultraviolet radiation of frequency 3.00x10^15 Hz. E=hv which is 6.626x1...
Thu Oct 19, 2017 7:52 pm
Forum: Properties of Light
Topic: Photoelectric Effect Module Question
Replies: 2
Views: 221

### Photoelectric Effect Module Question

Light hits a sodium metal surface and the velocity of the ejected electron is 6.61x10^15ms^-1. The work function for sodium is 150.6kJ.mol^-1. A.) What is the kinetic energy of the ejected electron? B.) How much energy is required to remove an electron from one sodium atom? C.) What is the frequency...
Fri Oct 13, 2017 11:43 am
Forum: Einstein Equation
Topic: Discussion Section Problem
Replies: 2
Views: 205

### Discussion Section Problem

During discussion section we were presented with this problem We have a frequency of v= 8.7x 10^14 Hz what is the energy? So we would need to first find the wavelength using the formula wavelength x frequency = velocity. Then rearranging the equation so that we can find the wavelength to plug that i...
Fri Oct 13, 2017 11:19 am
Forum: Properties of Light
Topic: Figure 1.9
Replies: 4
Views: 257

### Re: Figure 1.9

To add on to that our TA emphasized that we should know the EM spectrum. I assume that the location of the different types of radiation and know also the direction energy increases/decreases and frequency increases/decreases. This was also a question in the homework on Chapter 1.
Fri Oct 06, 2017 10:17 am
Forum: Limiting Reactant Calculations
Topic: Limiting Reactant Calculations [ENDORSED]
Replies: 3
Views: 620

### Limiting Reactant Calculations[ENDORSED]

For the following equation determine the limiting reagent if 21.4g NH3 is reacted with 42.5g of O2 First we check to see if the equation is balanced : 4NH3(g) + 5O2(g) -> 4NO(g) + 6H2O(g) Which the equation is balanced But what would be the next step to solving this problem? How would I calculate th...
Thu Oct 05, 2017 7:16 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity and Dilution [ENDORSED]
Replies: 7
Views: 952

### Molarity and Dilution[ENDORSED]

A solution is prepared by dissolving 55.1g of KCl in approximately 75mL of water and then adding water to a final volume of 125mL. What is the molarity of KCl(aq) in this solution? I know that Molarity equals: Molarity=moles of solute/ volume of the solution but in this case would we not use this fo...