Search found 31 matches

by DomMaiorca_1I
Tue Jun 12, 2018 7:57 pm
Forum: Bond Lengths & Energies
Topic: Bond Angles
Replies: 3
Views: 176

Re: Bond Angles

In this case I believe having your answer written as <109.5 is fine, my TA usually doesn't require us to be more specific than that unless the problem specifically states such.
by DomMaiorca_1I
Tue Jun 12, 2018 7:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Dipole Moments
Replies: 1
Views: 112

Dipole Moments

Will we be expected to calculate exact dipole moments on the final or will questions be limited to asking us to identify whether the compound is polar or non polar?
by DomMaiorca_1I
Sun Jun 10, 2018 9:39 pm
Forum: Properties & Structures of Inorganic & Organic Bases
Topic: Strong Base Ionization
Replies: 1
Views: 135

Strong Base Ionization

Are strong bases always completely ionized in water?

Thanks in advance!
by DomMaiorca_1I
Sun Jun 10, 2018 4:17 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: lecture 6/6 [ENDORSED]
Replies: 3
Views: 274

Re: lecture 6/6 [ENDORSED]

Oxides of Main Group Elements - As discussed, metal oxides react with water to form strong bases. - Many nonmetal oxides react with water to form acids. Carbon Dioxide + Water <—> Carbonic Acid CO2 (g) + H2O (l) <—> H2CO3 (aq) Sulfur Dioxide = Water <—> Sulphurous Acid SO2 (g) + H2O (l) <—> H2SO3 (a...
by DomMaiorca_1I
Sat Jun 09, 2018 8:34 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 787132

Re: Post All Chemistry Jokes Here

A photon checks into a hotel and is asked if he needs any help with his luggage. He says, "No, I'm traveling light."
by DomMaiorca_1I
Sat Jun 09, 2018 8:32 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 787132

Re: Post All Chemistry Jokes Here

If you're not part of the solution, you're part of the precipitate.
by DomMaiorca_1I
Sat Jun 09, 2018 8:29 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 787132

Re: Post All Chemistry Jokes Here

Did you hear Oxygen went on a date with Potassium?

It went OK.
by DomMaiorca_1I
Thu May 31, 2018 10:25 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Helpful Chart
Replies: 18
Views: 376

Helpful Chart

This post doesn't have a question, just a chart from my TA that might make memorization easier! # of regions of e- density. arrangement of e- densities (bond angles). 2 linear (180) 3 trigonal planar (120) 4 tetrahedral (109.5) 5 trigonal bipyramidal (120, 90) 6 octahedral (90)
by DomMaiorca_1I
Thu May 31, 2018 10:13 am
Forum: Hybridization
Topic: Hybridization
Replies: 2
Views: 69

Re: Hybridization

Hybridization is the concept of mixing atomic orbitals into new hybrid orbitals suitable for the pairing of electrons to form chemical bonds.
by DomMaiorca_1I
Thu May 31, 2018 10:10 am
Forum: Hybridization
Topic: VSEPR
Replies: 11
Views: 381

Re: VSEPR

Valence - Shell - Electron - Pair - Repulsion Model
by DomMaiorca_1I
Thu May 31, 2018 10:09 am
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR AXE
Replies: 4
Views: 105

VSEPR AXE

When using the VSEPR formula, knowing that for E you write the number of electron pairs, what would you write when dealing with a radical? Do you put E 0.5 or is it still E 1?

Thanks in advance!
by DomMaiorca_1I
Tue May 22, 2018 12:12 pm
Forum: Bond Lengths & Energies
Topic: Test 3 Material Question
Replies: 3
Views: 182

Re: Test 3 Material Question

I believe test 3 covers what we've learned in chapter 3 and those two small sections in chapter 6.

Hope this helps!
by DomMaiorca_1I
Fri May 18, 2018 9:42 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 787132

Re: Post All Chemistry Jokes Here

Helium walks into a bar.

The bar tender says, "We don't serve noble gasses in here."

Helium doesn't react.
by DomMaiorca_1I
Thu May 17, 2018 12:03 am
Forum: Ionic & Covalent Bonds
Topic: Formaldehyde Formula
Replies: 2
Views: 74

Formaldehyde Formula

Why is it that the chemical formula for formaldehyde is HCHO and not H2CO?
by DomMaiorca_1I
Thu May 17, 2018 12:01 am
Forum: Ionic & Covalent Bonds
Topic: Question 3.11
Replies: 1
Views: 82

Re: Question 3.11

It's pretty much just calculating the ground state in reverse. Knowing that the noble gas is Argon, the metal(s) must come from the fourth period of the periodic table since Argon is located in the third. a) 3d6 tells you there is 6 electrons, but you need to add an additional 3 since the question s...
by DomMaiorca_1I
Mon May 14, 2018 12:02 am
Forum: Lewis Structures
Topic: Formal Energy / Formal Charge [ENDORSED]
Replies: 2
Views: 92

Formal Energy / Formal Charge [ENDORSED]

Are formal energy and formal charge the same thing?
by DomMaiorca_1I
Mon May 14, 2018 12:00 am
Forum: Lewis Structures
Topic: Dots or lines [ENDORSED]
Replies: 5
Views: 122

Re: Dots or lines [ENDORSED]

My TA did this as well and he said it would be fine to do on a test or quiz since the two dots or the one line are referring to the same two electrons. He actually recommended using lines on the test instead of individual dots because it's a huge time saver if you're dealing with a complicated Lewis...
by DomMaiorca_1I
Sun May 13, 2018 11:46 pm
Forum: Resonance Structures
Topic: Number of Resonance Strucutres
Replies: 3
Views: 119

Re: Number of Resonance Strucutres

Finding the formal charge is usually a good indicator for how many resonance structures you'll have. For example, if you calculate the formal charges in PO4^3-, you find that P= +1 and 0= -1. Knowing the formal charges can cancel, and also that there are four times as many O as P, you know you'll ha...
by DomMaiorca_1I
Sun May 06, 2018 6:08 pm
Forum: Trends in The Periodic Table
Topic: Trends to Know
Replies: 12
Views: 392

Trends to Know

For the midterm, I know the important trends to know are atomic radii, ionic radii, and ionization energy. Are there any other trends I'm forgetting that we should definitely know? And if so, could you explain the trend?
by DomMaiorca_1I
Sun May 06, 2018 5:59 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm Topics [ENDORSED]
Replies: 33
Views: 1583

Re: Midterm Topics [ENDORSED]

Will we need to be able to draw electron configurations for the midterm?
by DomMaiorca_1I
Sun May 06, 2018 5:23 pm
Forum: Molarity, Solutions, Dilutions
Topic: Moles [ENDORSED]
Replies: 2
Views: 125

Re: Moles [ENDORSED]

"mole of solute stay the same" implies that even if the concentration of a substance is changed, if the same amount of the original substance is the same then the moles would remain unchanged. in terms of a practical example, if you have a cup of coke and you pour water into it, although t...
by DomMaiorca_1I
Sun Apr 22, 2018 4:38 pm
Forum: Photoelectric Effect
Topic: 1.25 part B
Replies: 2
Views: 88

1.25 part B

To find how much energy is emitted by 5.00mg of sodium atoms, do you have to convert the 5.00mg of sodium to atoms and then multiply by the energy found in part A? Thanks in advance.
by DomMaiorca_1I
Sun Apr 22, 2018 4:32 pm
Forum: Photoelectric Effect
Topic: 1.33 Part D
Replies: 2
Views: 91

1.33 Part D

(d) What kind of electromagnetic radiation was used?

For part C, I found a wavelength of 8.8. nm but I am unaware exactly how to find which region this falls into.
by DomMaiorca_1I
Sun Apr 22, 2018 12:18 pm
Forum: Photoelectric Effect
Topic: Energy spectrum
Replies: 4
Views: 116

Re: Energy spectrum

Each line represents a different jump in energy that an electron of an atom could make. The energy difference between these levels is given by the Rydberg formula.
by DomMaiorca_1I
Wed Apr 11, 2018 12:14 pm
Forum: Molarity, Solutions, Dilutions
Topic: Homework Problem G17
Replies: 2
Views: 98

Re: Homework Problem G17

Also, sorry if the -1's throw you off, the superscript button wasn't working correctly, but they're just there for unit notation.
by DomMaiorca_1I
Wed Apr 11, 2018 12:11 pm
Forum: Molarity, Solutions, Dilutions
Topic: Homework Problem G17
Replies: 2
Views: 98

Re: Homework Problem G17

This is similar to example G.2. For both a and b, since volume and molarity are given, you just multiply those quantities by the molar mass. (see formulas n = cV and m = nM) First, remember to convert 250 mL to 0.250L a) molar mass CuSO4 = 159.60 g/mol -1 mass of CuSO4 = (0.20mol/L -1) x (0.250L) x ...
by DomMaiorca_1I
Tue Apr 10, 2018 7:55 pm
Forum: SI Units, Unit Conversions
Topic: Units for Answer
Replies: 10
Views: 372

Re: Units for Answer

In this problem specifically (L.35), the question asks for your answer in kilograms. If the question didn't ask for your answer in kg, it would be okay to leave your answer in grams. If you are ever unsure, you could just write your answer as " 5.09 x 10^5 g Fe or 509 kg Fe ", since it's u...
by DomMaiorca_1I
Tue Apr 10, 2018 7:44 pm
Forum: Molarity, Solutions, Dilutions
Topic: Fundamentals HW G.13
Replies: 1
Views: 106

Fundamentals HW G.13

G.13 To prepare a fertilizer solution, a florist dilutes 1.0L of 0.20M NH4NO3 (aq) by adding 3.0L of water. The florist then adds 100. mL of the diluted solution to each plant. How many moles of nitrogen atoms will each plant receive? I first used M1V1 = M2V2 to find the concentration of diluted NH4...
by DomMaiorca_1I
Tue Apr 10, 2018 5:01 pm
Forum: Significant Figures
Topic: Scientific notation [ENDORSED]
Replies: 7
Views: 293

Re: Scientific notation [ENDORSED]

Sig figs should be enough, but for really small or really large numbers I would use scientific notation to be concise.
by DomMaiorca_1I
Tue Apr 10, 2018 4:58 pm
Forum: Molarity, Solutions, Dilutions
Topic: Question on Self Test G.3A
Replies: 1
Views: 63

Re: Question on Self Test G.3A

Micromol and millimol differ by a factor of 1000. Therefore, to go from mol to mmol, divide 1.44umol by 1000 to get 0.0014 mmol.
by DomMaiorca_1I
Sat Apr 07, 2018 1:36 pm
Forum: Molarity, Solutions, Dilutions
Topic: HW G.7
Replies: 2
Views: 94

Re: HW G.7

I'm pretty sure it doesn't need to be completely dissolved.

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