Search found 39 matches

by tmehrazar
Wed Jun 13, 2018 2:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Worksheet 9 #1
Replies: 1
Views: 129

Worksheet 9 #1

why is the answer in the key the most stable lewis structure for NO2, wouldn't having another double bond between N and the other O make all of its formal charges 0 hence more stable?
by tmehrazar
Wed Jun 13, 2018 1:41 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: French Toast #25 [ENDORSED]
Replies: 1
Views: 138

French Toast #25 [ENDORSED]

How do we find the oxidation state for platinum in [Pt(Cl)2(NH3)2]?
by tmehrazar
Sun Jun 10, 2018 9:27 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelating complex
Replies: 7
Views: 168

Re: Chelating complex

yes like if its a long string of atoms coming out of two sides of the central atom, you can imagine it would bend and make a chelate if a metal comes and connects each end
by tmehrazar
Sun Jun 10, 2018 9:23 pm
Forum: Properties of Electrons
Topic: Wave-like Properties of Electron
Replies: 5
Views: 195

Re: Wave-like Properties of Electron

where did that number come from, is it just something to know or is there a reason behind it?
by tmehrazar
Sun Jun 10, 2018 9:23 pm
Forum: Octet Exceptions
Topic: expanded octet
Replies: 12
Views: 448

Re: expanded octet

I know for sure non-metals have expanded octets so definitely not only transition metals. In the review today the TA said anything group 3 and lower can have an expanded octet so I think that's the most important thing to know.
by tmehrazar
Sun Jun 03, 2018 10:58 pm
Forum: Naming
Topic: Naming on Final
Replies: 8
Views: 316

Re: Naming on Final

no we don't need to know names of molecules, the professor mentioned this in the last class and he said just to ignore that part of book problems, but you're talking about naming molecules right?
by tmehrazar
Sun Jun 03, 2018 10:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular vs. VSEPR shape
Replies: 3
Views: 69

Re: Molecular vs. VSEPR shape

What do you mean, like the lewis structure?
by tmehrazar
Sun Jun 03, 2018 1:14 pm
Forum: Lewis Structures
Topic: Test Q.8 [ENDORSED]
Replies: 7
Views: 249

Re: Test Q.8 [ENDORSED]

sorry I'm still a little confused about this, can anyone further explain what resonance structures mean for the bond lengths
by tmehrazar
Wed May 23, 2018 10:59 pm
Forum: Lewis Structures
Topic: Homework Problem 3.59
Replies: 2
Views: 80

Re: Homework Problem 3.59

got it!
by tmehrazar
Wed May 23, 2018 8:11 pm
Forum: Lewis Structures
Topic: Homework Problem 3.59
Replies: 2
Views: 80

Homework Problem 3.59

in part a, how do you know that in the lewis structure for ClO, Cl has one lone electron and not O? or does it not matter?
by tmehrazar
Wed May 23, 2018 8:01 pm
Forum: Lewis Structures
Topic: Homework Problem 3.65
Replies: 3
Views: 93

Homework Problem 3.65

i understand the problem, but how are we supposed to know the oxygens get double bonded in the lewis structures?
by tmehrazar
Wed May 23, 2018 11:48 am
Forum: Lewis Structures
Topic: Homework 3.39 part b
Replies: 2
Views: 115

Homework 3.39 part b

b) write the complete lewis structure for the compound potassium phosphide

could somebody explain their work on this question please, I'm having trouble with it
by tmehrazar
Sun May 20, 2018 10:53 pm
Forum: Bond Lengths & Energies
Topic: 3.87
Replies: 5
Views: 215

Re: 3.87

can someone also explain how to fully do this question!
by tmehrazar
Sun May 20, 2018 10:46 pm
Forum: Ionic & Covalent Bonds
Topic: Test 3 [ENDORSED]
Replies: 7
Views: 228

Re: Test 3 [ENDORSED]

i think it'll be clearly stated in the question
by tmehrazar
Sun May 20, 2018 10:17 pm
Forum: Significant Figures
Topic: Sig Figs
Replies: 3
Views: 189

Re: Sig Figs

basically you can only give an answer with the same amount of sig figs as the number you used in your calculations with the lowest sig figs, this is because if you have a less precise number you can't report a more precise result an example is if you used 4.000(4sf) and 5.0000(5sf) in your calculati...
by tmehrazar
Sun May 20, 2018 9:57 pm
Forum: Lewis Structures
Topic: Formal Charge
Replies: 4
Views: 131

Re: Formal Charge

what works for me is just doing valence electrons - nonbonding electrons - bonding electrons/2
i just try to remember the total you have is the valence, then you remove the lone electrons you used, then the bonding electrons divided by 2 because they're shared
by tmehrazar
Tue May 08, 2018 8:25 pm
Forum: DeBroglie Equation
Topic: test 2, question5
Replies: 5
Views: 317

Re: test 2, question5

I'm not sure, but I got 1.550 x 10^-10m and I got that from (6.626x10^-34Js)/(3.818x10^-26kg)(112ms^-1)

I got 3.818x10^-26kg by multiplying 22.99g Na/1mol Na x 1mol Na/6.022x10^23 x 1kg/1000g

Not 100% I'm right though

Can anyone validate this?
by tmehrazar
Tue May 08, 2018 2:53 pm
Forum: Trends in The Periodic Table
Topic: 2.81
Replies: 3
Views: 173

Re: 2.81

So although the trend is increasing from left to right and down to up for ionization energy, atoms that are stable, meaning either they have all unpaired electrons in their shells or all paired, have a higher ionization energy because when it is stable, it's harder to remove an electron meaning it h...
by tmehrazar
Tue May 08, 2018 2:38 pm
Forum: Trends in The Periodic Table
Topic: Does Sulfur or Phosphorus have a larger ionization energy?
Replies: 3
Views: 813

Re: Does Sulfur or Phosphorus have a larger ionization energy?

I think phosphorus does have a higher ionization energy because when you look at the shells filled up, sulfur has one pair of electrons and phosphorus has all unpaired electrons. Either all unpaired or all paired makes it stable, so if phosphorus is all unpaired it take more energy to remove an elec...
by tmehrazar
Sun May 06, 2018 12:11 pm
Forum: Limiting Reactant Calculations
Topic: Test #1 Q. 5
Replies: 2
Views: 182

Re: Test #1 Q. 5

I had a different version, but I'm pretty sure the way to do this problem is: 10.0g malrotriose x 1 mol maltotriose/504.437g maltotriose x 18mol O2/1 mol maltotriose x 32g O2/1 mol O2 = 11.42g O2 each denominator for the fractions cancels out the numerator of the previous fraction, so you're left wi...
by tmehrazar
Sun May 06, 2018 11:13 am
Forum: Quantum Numbers and The H-Atom
Topic: Midterm Review Q5 part f [ENDORSED]
Replies: 2
Views: 157

Re: Midterm Review Q5 part f [ENDORSED]

got it thanks!
by tmehrazar
Sat May 05, 2018 12:44 pm
Forum: Photoelectric Effect
Topic: Midterm Review Q4
Replies: 2
Views: 126

Re: Midterm Review Q4

thank you!! (: def helps
by tmehrazar
Sat May 05, 2018 12:42 pm
Forum: Quantum Numbers and The H-Atom
Topic: Midterm Review Q5 part f [ENDORSED]
Replies: 2
Views: 157

Midterm Review Q5 part f [ENDORSED]

5. f) How many electrons can have the quantum numbers n=3, l=1?

Why is the answer to this 6?
by tmehrazar
Sat May 05, 2018 9:25 am
Forum: Photoelectric Effect
Topic: Midterm Review Q4
Replies: 2
Views: 126

Midterm Review Q4

4. a) Write an equation using words only that captures the conservation of energy in the photoelectric effect. Describe the conceptual change that arose from the photoelectric experiment and discuss how intensity plays a role. I got the equation, but how do you describe the conceptual change and how...
by tmehrazar
Sat May 05, 2018 8:25 am
Forum: Limiting Reactant Calculations
Topic: Midterm Review Q2
Replies: 7
Views: 1038

Midterm Review Q2

2. Ammonia (NH3) reacts with oxygen (O2) to form air pollutant nitrogen oxide (NO) and water. Determine the theoretical yield of NO if 21.1 g NH3 is reacted with 42.2 g O2.

I missed the first part of the review session, is the answer to this 7.9g NO?
by tmehrazar
Sat May 05, 2018 7:54 am
Forum: Limiting Reactant Calculations
Topic: Homework M12
Replies: 3
Views: 220

Homework M12

For part c on homework problem M12, do we find the excess amount of reactant by subtracting the original amount of Al by the amount of Al we get when we convert Fe0 to grams of Al since FeO was the limiting reactant? If this works, are there other ways to find the excess reactant leftover?
by tmehrazar
Sun Apr 29, 2018 1:26 pm
Forum: Photoelectric Effect
Topic: What is work function? [ENDORSED]
Replies: 15
Views: 1026

Re: What is work function? [ENDORSED]

i was confused about this too, so it's just that equation?
by tmehrazar
Sun Apr 29, 2018 1:18 pm
Forum: DeBroglie Equation
Topic: Test #2: Q5 [ENDORSED]
Replies: 9
Views: 461

Re: Test #2: Q5 [ENDORSED]

looks right to me!
by tmehrazar
Sat Apr 28, 2018 11:23 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Why does the 4s orbital come before the 3d?
Replies: 7
Views: 225

Re: Why does the 4s orbital come before the 3d?

the 4s orbitals have lower energy than the 3d orbitals not the other way around, some things online say that s-orbitals are more penetrating than d-orbitals so i think that may be why
by tmehrazar
Sun Apr 22, 2018 10:09 pm
Forum: Balancing Chemical Reactions
Topic: Q4
Replies: 3
Views: 180

Q4

How do you do question 4 on test 1? Writing a balanced equation for the combustion of fluorene.
by tmehrazar
Sun Apr 22, 2018 10:02 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: 1.43
Replies: 1
Views: 82

1.43

What is the minimum uncertainty in the speed of an electron confined to within a lead atom of diameter 350. pm? Model the atom as a one-dimensional box with a length equal to the diameter of the actual atom.

How do you do this problem i'm having some trouble?
by tmehrazar
Sun Apr 22, 2018 9:39 pm
Forum: Balancing Chemical Reactions
Topic: Help with homework problem L.39 [ENDORSED]
Replies: 2
Views: 169

Re: Help with homework problem L.39 [ENDORSED]

got it thanks!!
by tmehrazar
Wed Apr 18, 2018 11:49 pm
Forum: DeBroglie Equation
Topic: 1.41 [ENDORSED]
Replies: 3
Views: 168

Re: 1.41 [ENDORSED]

thanks guys this helped! (:
by tmehrazar
Sun Apr 15, 2018 9:01 pm
Forum: Empirical & Molecular Formulas
Topic: Finding Empirical and Molecular Formula [ENDORSED]
Replies: 6
Views: 369

Re: Finding Empirical and Molecular Formula [ENDORSED]

I think you count how many of each atom you have for the molecular formula and then simplify that by it's least common denominator.
by tmehrazar
Sun Apr 15, 2018 8:16 pm
Forum: Properties of Light
Topic: HW chapter 1 question 3
Replies: 5
Views: 268

Re: HW chapter 1 question 3

The question asks: Which of the following happens when the frequency of electromagnetic radiation decreases? Explain your reasoning. a) the speed of radiation decreases b) the wavelength of the radiation decreases c) the extent of the change in the electrical field at a given point decreases d) the ...
by tmehrazar
Sun Apr 15, 2018 8:06 pm
Forum: SI Units, Unit Conversions
Topic: Avogadro's Number [ENDORSED]
Replies: 11
Views: 406

Re: Avogadro's Number [ENDORSED]

Yes it can be used for both and it does depend on the basic units of the substance.
by tmehrazar
Sun Apr 15, 2018 8:03 pm
Forum: Empirical & Molecular Formulas
Topic: Finding Molecular X
Replies: 9
Views: 311

Re: Finding Molecular X

What do you mean exactly, could you provide an example?
by tmehrazar
Sun Apr 15, 2018 8:01 pm
Forum: DeBroglie Equation
Topic: 1.41 [ENDORSED]
Replies: 3
Views: 168

1.41 [ENDORSED]

What is the velocity of a neutron of wavelength 100.pm?

Do we have enough info to answer this question?
by tmehrazar
Sun Apr 15, 2018 7:43 pm
Forum: Balancing Chemical Reactions
Topic: Help with homework problem L.39 [ENDORSED]
Replies: 2
Views: 169

Help with homework problem L.39 [ENDORSED]

A 1.50g of metallic tin was placed in 26.46g crucible and heated until all of the tin had reacted with the oxygen in air to form an oxide. The crucible and product together were found to weigh 28.35g. a) what is the empirical formula of the oxide? b) write the name of the oxide. I'm pretty confused ...

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