## Search found 20 matches

Mon May 21, 2018 7:32 pm
Forum: Lewis Structures
Topic: Friday's Lecture [ENDORSED]
Replies: 4
Views: 288

### Re: Friday's Lecture[ENDORSED]

Test 3 will only cover material from chapter 3.
Mon May 21, 2018 7:30 pm
Forum: Ionic & Covalent Bonds
Topic: Formal Charge
Replies: 3
Views: 192

### Re: Formal Charge

I believe that we should use the formal charge equation that was given to us in class instead.
Mon May 14, 2018 9:53 pm
Forum: Lewis Structures
Topic: BF3
Replies: 2
Views: 196

### Re: BF3

Boron is an exception and is fine with only six valence electron in its outer shell.
Mon May 14, 2018 8:57 pm
Forum: Ionic & Covalent Bonds
Topic: Electronegativity
Replies: 5
Views: 341

### Re: Electronegativity

I also believe that you would need to look at more properties other than electronegativity to determine the type of bond.
Mon May 14, 2018 8:33 pm
Forum: Ionic & Covalent Bonds
Topic: 3.23 (meaning of oxidation)
Replies: 7
Views: 420

### Re: 3.23 (meaning of oxidation)

In general, the oxidation state is the number of electrons an atom gains, loses, or shares when it forms a chemical bond. The maximum positive oxidation state for chlorine would be +7. While the maximum negative oxidation state for chlorine is -1.
Fri May 11, 2018 9:41 pm
Forum: Ionic & Covalent Bonds
Topic: Difference between anions and cations?
Replies: 3
Views: 232

### Re: Difference between anions and cations?

Cations give up electrons in order to reach octet. Anions form ions that are larger than their original atoms. Also, anions are negatively charged ions, while cations are positively charged ions.
Sun May 06, 2018 10:09 pm
Forum: Einstein Equation
Topic: Difference Between Equations
Replies: 4
Views: 273

### Re: Difference Between Equations

In the E=hv equation, v stands for the frequency of photons. However, for the equation E=1/2mv^2 the v stands for the velocity of an electron.
Sun May 06, 2018 9:35 pm
Forum: Properties of Light
Topic: The visible spectrum
Replies: 4
Views: 335

### Re: The visible spectrum

A continuous spectrum is the emission of a continuous range of frequencies of electromagnetic radiation.
A line spectrum shows a series of specific wavelengths of emitted light made when the visible part of light from excited atoms shine through a prism.
Sun May 06, 2018 9:18 pm
Forum: Properties of Light
Topic: 4b practice midterm
Replies: 11
Views: 902

### Re: 4b practice midterm

I believe that you have to use the De Broglie equation for this problem, since the wavelength is given for a moving electron in this problem, in order to get the correct answer.
Sun Apr 29, 2018 9:28 pm
Forum: Einstein Equation
Topic: Hw problem 1.59 [ENDORSED]
Replies: 3
Views: 334

### Re: Hw problem 1.59[ENDORSED]

You have to use E=hc/λ. Then, plug in the constants for h and c a and the given wavelength for lambda will get you the energy per photon.Next, you multiply by the given number of photons to get the total energy produced.
Sun Apr 29, 2018 9:22 pm
Forum: Einstein Equation
Topic: Difference Between Equations [ENDORSED]
Replies: 4
Views: 330

### Re: Difference Between Equations[ENDORSED]

Basically, E=hc/λ is just the derived version of E=hv because v=c/λ.
Sun Apr 29, 2018 9:17 pm
Forum: Properties of Electrons
Topic: Mass of an Electron [ENDORSED]
Replies: 4
Views: 307

### Re: Mass of an Electron[ENDORSED]

The mass of an electron is 9.1095 x 10^-31 kg.
Sun Apr 29, 2018 9:13 pm
Forum: Properties of Light
Topic: Homework Problem(s) [ENDORSED]
Replies: 6
Views: 315

### Re: Homework Problem(s)[ENDORSED]

The masses of both of these will be on the equation sheet.
Sun Apr 29, 2018 9:12 pm
Forum: Properties of Light
Topic: Test #2: Q6 [ENDORSED]
Replies: 10
Views: 771

### Re: Test #2: Q6[ENDORSED]

In addition, I also used E=hv and wavelength=c/v and came up with the same answer. But also using wavelenght=hc/E can work as well.
Mon Apr 16, 2018 1:20 pm
Forum: Properties of Light
Topic: Photon units? [ENDORSED]
Replies: 4
Views: 254

### Re: Photon units?[ENDORSED]

Also, I think that the units for a photon are in joules (J).
Mon Apr 16, 2018 1:17 pm
Forum: SI Units, Unit Conversions
Replies: 9
Views: 707

By definition avogadro's number is exactly 6.022 times 10^23. This constant is used in stoichoimetry. For instance, it is used to convert from moles to atoms. Such as multplying the molar mass by avagadro's number.
Mon Apr 16, 2018 1:09 pm
Forum: Limiting Reactant Calculations
Topic: Reactant vs. Reagent [ENDORSED]
Replies: 23
Views: 18527

### Re: Reactant vs. Reagent[ENDORSED]

Reactant and reagent are frequently used in chemistry problems. However, reagents are compounds that are added in order to check if a chemistry reaction will take place, and reactants is a substance involved in a chemistry reaction.
Fri Apr 06, 2018 11:09 pm
Forum: Molarity, Solutions, Dilutions
Topic: G.5 part a [ENDORSED]
Replies: 3
Views: 215

### Re: G.5 part a[ENDORSED]

Agreed, in part a it states 2.15 mil which means millimole. So, the conversion factor is 1,000 millimoles in 1 mole.Thats why they used 2.15 x 10^-3.
Fri Apr 06, 2018 11:04 pm
Forum: Limiting Reactant Calculations
Topic: M.5
Replies: 4
Views: 235

### Re: M.5

In order to determine how much of the excess reactant will be produced , you must use the mass of the limiting reactant. Next, subtract the original amount of the excess reactant at first by how much excess reactant was made.
Fri Apr 06, 2018 10:58 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Which mass of oxygen should be used? [ENDORSED]
Replies: 23
Views: 1360

### Re: Which mass of oxygen should be used?[ENDORSED]

I’m sure you can use 16.00 for the mass of the oxygen. Either 15.99 or 16.00 are fairly close, but Dr. Lavelle used 16.00 in his example.