Search found 31 matches

by yaosamantha4F
Sat Dec 08, 2018 2:17 pm
Forum: Empirical & Molecular Formulas
Topic: Midterm Solutions Fall 2018-2019 year
Replies: 2
Views: 59

Re: Midterm Solutions Fall 2018-2019 year

Is this the problem about the empirical/molecular formulas of gallic acid? After calculating the number of g of H produced through combustion using the molar mass of H2O and the molar ratio of H and H2O, you divide by H's molar mass (1.007) to find the number of moles!
by yaosamantha4F
Sat Dec 08, 2018 1:20 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 11
Views: 151

Re: Polydentate

I believe carbonato is bidentate!
by yaosamantha4F
Sat Dec 08, 2018 1:15 pm
Forum: Naming
Topic: memorizing complexes?
Replies: 2
Views: 36

Re: memorizing complexes?

I would memorize them just to be safe!
by yaosamantha4F
Sun Dec 02, 2018 11:48 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Grades
Replies: 10
Views: 166

Re: Final Grades

If you get at least 250 points, you're guaranteed a C-. I believe Dr. Lavelle said he would work out the specific letter grade/point distributions after the final?
by yaosamantha4F
Sun Dec 02, 2018 11:44 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw
Replies: 13
Views: 167

Re: Seesaw

The bond angles for a seesaw shape will be a little bit less than 90 and 120 degrees due to the lone pairs' repulsion pushing the bonds slightly.
by yaosamantha4F
Sat Nov 24, 2018 11:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: double and triple bonds
Replies: 10
Views: 87

Re: double and triple bonds

Single, double, and triple bonds all count as one region of electron density, so the bond type doesn't affect naming using VSEPR.
by yaosamantha4F
Sat Nov 24, 2018 11:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Naming the Shape
Replies: 16
Views: 159

Re: Naming the Shape

I think it's helpful but not 100% necessary to memorize the bond angles, since you can usually determine them by visualizing the shape.
by yaosamantha4F
Sat Nov 24, 2018 11:01 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sigma and Pi bonds
Replies: 6
Views: 48

Re: Sigma and Pi bonds

Adding on, because sigma bonds overlap end-to-end, they allow bound atoms to rotate, while pi bonds, which overlap side-to-side, do not allow bound atoms to rotate. Sigma bonds are also formed between atoms, while pi bonds are formed above/under/beside sigma bonds.
by yaosamantha4F
Sun Nov 18, 2018 8:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape vs. Electron Geometry
Replies: 4
Views: 50

Re: Molecular Shape vs. Electron Geometry

Electron geometry refers to how electron groups are arranged, while molecular shape how all the atoms in a molecule are arranged. Lone and bonding electron pairs are considered in electron geometry, while molecular shape only considers bonding electron pairs. For example, using electron geometry, a ...
by yaosamantha4F
Sun Nov 18, 2018 8:28 pm
Forum: Student Social/Study Group
Topic: Turning in Homework (Thanksgiving Break)
Replies: 8
Views: 137

Re: Turning in Homework (Thanksgiving Break)

We just need to submit 14 problems (for both week 8 and week 9) the week after we get back from break!
by yaosamantha4F
Sat Nov 10, 2018 5:25 pm
Forum: Lewis Structures
Topic: Atoms with 8+ valence e-
Replies: 6
Views: 177

Re: Atoms with 8+ valence e-

The energy between the 3d and 4s orbitals is not very big, so the d-orbitals can take in additional e- to give an expanded octet. In the first and second periods of the periodic table, no d-orbital exists, but starting with the third period, the d-orbital is present and can accomodate additional e-.
by yaosamantha4F
Sat Nov 10, 2018 5:15 pm
Forum: Limiting Reactant Calculations
Topic: Actual Yield
Replies: 7
Views: 200

Re: Actual Yield

Actual yield is calculated based off of the results of an experiment while theoretical yield is calculated based off of the complete reaction of the limiting reactant. Actual yield should be given to us in any problem that requires it since it's impossible to determine without conducting the experim...
by yaosamantha4F
Sat Nov 03, 2018 1:44 am
Forum: Limiting Reactant Calculations
Topic: Midterm Review Q2
Replies: 7
Views: 772

Re: Midterm Review Q2

First, calculate the molar mass of KMnO4 (158.09g/mol). Next, concert 5g KMnO4 to moles and 150mL to L and use the formula M=mol/L to calculate the molarity of the first solution. Lastly, use the equation M1V1=M2V2 equation to calculate the concentration of the second flask by using the value you pr...
by yaosamantha4F
Fri Nov 02, 2018 12:59 am
Forum: Ionic & Covalent Bonds
Topic: Ionic vs Covalent Bonds
Replies: 18
Views: 221

Re: Ionic vs Covalent Bonds

Ionic bonds are usually formed between a metal and a nonmetal; the metal loses electrons are transferred to the nonmetal so that both atoms can have the same electron configuration as the preceding/following noble gas. Covalent bonds, on the other hand, involve electrons being shared between atoms t...
by yaosamantha4F
Fri Nov 02, 2018 12:56 am
Forum: Ionic & Covalent Bonds
Topic: Group Me
Replies: 2
Views: 50

Re: Group Me

There's also a Facebook Messenger chat that's fairly active!
by yaosamantha4F
Sun Oct 28, 2018 8:39 pm
Forum: Ionic & Covalent Bonds
Topic: 2A.21 7th Edition Question
Replies: 2
Views: 26

Re: 2A.21 7th Edition Question

The normal ground state configuration for Ag is [Kr]4d^10 5s^1. Based off of the Aufbau principle, silver's expected configuration would be [Kr]4d^9 5s^2, but since a full or half-full subshell is more stable than a partially-filled one, the s electron is transferred to the d orbital since having th...
by yaosamantha4F
Sun Oct 28, 2018 5:57 pm
Forum: Ionic & Covalent Bonds
Topic: Friday 10/26/18 lecture
Replies: 4
Views: 62

Re: Friday 10/26/18 lecture

He focused mainly on the differences between ionic and covalent bonds and how they each achieved the octet rule, and also demonstrated how to draw several different Lewis structures.
by yaosamantha4F
Sun Oct 28, 2018 5:52 pm
Forum: Ionic & Covalent Bonds
Topic: Trend of Ionic Radii
Replies: 5
Views: 58

Re: Trend of Ionic Radii

Ionic radii increase in size down a group (column) since more shells means that valence electrons are further away from the nucleus and decrease across a period (row) since atoms' increased nuclear charge means that they will pull their electrons in more closely (shell contraction).
by yaosamantha4F
Sat Oct 20, 2018 11:39 pm
Forum: DeBroglie Equation
Topic: DeBroglie Equation Post Assessment
Replies: 4
Views: 133

Re: DeBroglie Equation Post Assessment

That should be correct, although when you're plugging numbers into your calculator, make sure to put parentheses around (m*wavelength). It is not reasonable for an electron to be faster than the speed of light, but if the electron is below 10^5m/s, this may also be too slow to be reasonable.
by yaosamantha4F
Sat Oct 20, 2018 11:16 pm
Forum: Properties of Light
Topic: Calculating the wavelength of light
Replies: 7
Views: 81

Re: Calculating the wavelength of light

Both are okay to use but 2.998*10^8 m/s will give you a more accurate answer!
by yaosamantha4F
Thu Oct 18, 2018 9:12 am
Forum: Einstein Equation
Topic: Question 1.65 (Sixth Edition)
Replies: 1
Views: 46

Re: Question 1.65 (Sixth Edition)

Starting with 348kJ/mol, you would multiply by 348kJ/mol C-C bonds * 1mol C-C bonds/6.022*10^23 C-C bonds *1000J/kJ to ultimately end up 5.78*10^(-19)J as ΔE. You can then use the equation λ=hc/ΔE and plug in Planck's constant, the speed of light, and ΔE to get 3.44*10^-7m (or 344nm). This falls und...
by yaosamantha4F
Sun Oct 14, 2018 4:38 pm
Forum: Significant Figures
Topic: When to round the answers to significant figures
Replies: 11
Views: 248

Re: When to round the answers to significant figures

I would try to round at the very end whenever possible! Keeping more sig figs in your calculations allows you to end up with a more accurate final result.
by yaosamantha4F
Thu Oct 11, 2018 11:56 pm
Forum: Balancing Chemical Reactions
Topic: L.5 Part B Sixth Edition [ENDORSED]
Replies: 5
Views: 123

Re: L.5 Part B Sixth Edition [ENDORSED]

Your steps look right; maybe double check that you're using the right molar masses and inputting the correct numbers into your calculator?
by yaosamantha4F
Thu Oct 11, 2018 10:47 am
Forum: Balancing Chemical Reactions
Topic: Chemical compounds
Replies: 3
Views: 139

Re: Chemical compounds

I would go with whatever your TA says to your discussion section; our TA specified that we would be given formulas for any chemical compounds!
by yaosamantha4F
Fri Oct 05, 2018 12:03 am
Forum: Limiting Reactant Calculations
Topic: Comparing Calculated Moles step M7(b)
Replies: 2
Views: 66

Re: Comparing Calculated Moles step M7(b)

If you go ahead and balance the chemical equation first, you get B2O3 + 3Mg(s) -> 3MgO(s) + 2B(s). You then need to calculate the mass of boron that is produced from both Mg and B2O3. First, convert the masses of both from kg to g, divide by the molar mass of the compound, multiply by the ratio of B...
by yaosamantha4F
Thu Oct 04, 2018 11:55 pm
Forum: Balancing Chemical Reactions
Topic: Mole Coefficients in Chemical Equations
Replies: 6
Views: 145

Re: Mole Coefficients in Chemical Equations

The coefficients are used to represent the number of atoms/molecules on each side! With coefficients of 2, 2, 2, and 1, both sides of the reaction end up with 2 atoms of Na, 4 atoms of H, and 2 atoms of O.
by yaosamantha4F
Thu Oct 04, 2018 11:46 pm
Forum: Significant Figures
Topic: sig figs urgent question!
Replies: 12
Views: 332

Re: sig figs urgent question!

1.001 has 4 significant figures! A trick I use to remember which numbers to count as sig figs is the the Atlantic/Pacific analogy. If there's a decimal point present, start from the left (since the Pacific ocean is on the left/west coast of the US) and count starting from the first non-zero number. ...

Go to advanced search