Search found 33 matches

by Javier_Ochoa_DIS_3J
Fri Dec 07, 2018 5:17 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids
Replies: 2
Views: 180

Re: Bronsted Acids

Bronsted acids just proton donators. It does not matter the atoms as long as it fulfills this definition.
by Javier_Ochoa_DIS_3J
Fri Dec 07, 2018 5:10 pm
Forum: Bronsted Acids & Bases
Topic: acidity
Replies: 4
Views: 114

Re: acidity

The longer the bond the more stable the acid is. The resulting conjugate base does not want to attract the H after disassociating.
by Javier_Ochoa_DIS_3J
Fri Dec 07, 2018 5:07 pm
Forum: Bronsted Acids & Bases
Topic: Identifying the difference
Replies: 6
Views: 101

Re: Identifying the difference

There are two definition you can use for acid and bases.
The Bronsted definition deals with the transfer of protons and the Lewis definition deals with the transfer of electrons.
by Javier_Ochoa_DIS_3J
Sun Dec 02, 2018 12:10 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Bromine Electron Configuration
Replies: 2
Views: 2039

Re: Bromine Electron Configuration

Ground state electron configuration starts from the beginning 1s2.
by Javier_Ochoa_DIS_3J
Sun Dec 02, 2018 12:04 pm
Forum: General Science Questions
Topic: Final Review
Replies: 4
Views: 140

Re: Final Review

I felt all the workshops I have been too were super helpful. You can't go wrong with Karen Leung though.
by Javier_Ochoa_DIS_3J
Sun Dec 02, 2018 12:00 pm
Forum: Air Pollution & Acid Rain
Topic: Acid Rain
Replies: 3
Views: 278

Re: Acid Rain

I don't know about the globe but I found some in formation about Acid Rain in the US https://water.usgs.gov/edu/acidrain.html It states that acid rain is usually a pH of 5.0-5.5 It also states that in the Northeast there can be rain with the pH of 4.0 I assume that in many places around the globe th...
by Javier_Ochoa_DIS_3J
Sat Nov 24, 2018 1:35 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: double and triple bonds
Replies: 10
Views: 138

Re: double and triple bonds

single, double, and triple bonds are all the same when using the VSEPR model.
by Javier_Ochoa_DIS_3J
Sat Nov 24, 2018 1:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: polarity
Replies: 3
Views: 83

Re: polarity

I believe if it's fully symmetric than it would have to be non-polar considering an equal force on all sides. I am sure there are exceptions but I doubt we have to know them now.
by Javier_Ochoa_DIS_3J
Sat Nov 24, 2018 1:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: vsepr model
Replies: 3
Views: 69

Re: vsepr model

Electron Geometry is what the shape is considering all the regions of e- density including lone pairs and connected atoms to the center element. Molecular geometry is the shape considering only the connected atoms but while still using the electron repulsion of the lone pairs. In case my wording is ...
by Javier_Ochoa_DIS_3J
Thu Nov 15, 2018 9:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Memorizing the VSPER Models
Replies: 4
Views: 119

Re: Memorizing the VSPER Models

Another easy way to memorize VSPER shapes is to memorize which ones correspond to which VSPER formula.
by Javier_Ochoa_DIS_3J
Thu Nov 15, 2018 9:08 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Vespr Formula
Replies: 6
Views: 99

Re: Vespr Formula

Here is an example to help.

The formula is all about what is connected to the center atom. The number after X means the number elements attached to the center element. E represents the number of electron lone pairs attached to the center element.

I hope that helped a little.
by Javier_Ochoa_DIS_3J
Thu Nov 15, 2018 9:02 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Double Bonds in VSEPR
Replies: 5
Views: 71

Re: Double Bonds in VSEPR

Single, double, and triple bonds are all the same when it comes to the molecular shape.
by Javier_Ochoa_DIS_3J
Thu Nov 15, 2018 8:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Sulfite Ion?
Replies: 2
Views: 67

Re: Sulfite Ion?

It is slightly less at 106 because the lone pair attached to the center atom has a stronger repulsion force than if it was another element.

So usually we would expect 109.5 degrees but since we know a lone pair pushes the atoms slightly harder we know the angle is going to be a little smaller.
by Javier_Ochoa_DIS_3J
Sun Nov 11, 2018 7:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 12
Views: 244

Re: Bond Angles

I assume that if we are expected to memorize the angles it would be the most commons ones.
by Javier_Ochoa_DIS_3J
Sun Nov 11, 2018 7:01 pm
Forum: Lewis Acids & Bases
Topic: Determine Lewis Acid
Replies: 13
Views: 536

Re: Determine Lewis Acid

A lewis Acids accepts electrons.
by Javier_Ochoa_DIS_3J
Sun Nov 11, 2018 4:42 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid vs base [ENDORSED]
Replies: 15
Views: 263

Re: Acid vs base [ENDORSED]

Lewis bases give electrons and Lewis acids receive electrons.
by Javier_Ochoa_DIS_3J
Sat Nov 03, 2018 10:29 pm
Forum: Administrative Questions and Class Announcements
Topic: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]
Replies: 121
Views: 5110

Re: MIDTERM PRACTICE - Garlic Bread Review Session [ENDORSED]

Will someone explain 8b? I know that we need to use all of the information given in the question but I am not sure how wavelength corresponds to work functions. Thank you! So the main equation you need is Eph = (work function of metal) - Ek (energy of electron ejected) This is not correct. See post...
by Javier_Ochoa_DIS_3J
Thu Nov 01, 2018 4:50 pm
Forum: Lewis Structures
Topic: Expanded octets
Replies: 6
Views: 209

Re: Expanded octets

Any element below N=3 can have an expanded octet.
by Javier_Ochoa_DIS_3J
Thu Nov 01, 2018 4:46 pm
Forum: Lewis Structures
Topic: Lewis Structures- formal charge
Replies: 4
Views: 121

Re: Lewis Structures- formal charge

This is the equation to find the formal charge.

Valance electrons - (lone pair electrons + number of bonds) = Formal charge.
by Javier_Ochoa_DIS_3J
Thu Nov 01, 2018 4:43 pm
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 4
Views: 107

Re: Lewis Structures

Any element in the 13th column does not need to have a full octet. This would include B, Al, Ga, In, Ti, and Nh.

However they are allowed to have 8 if the compound needs it.
by Javier_Ochoa_DIS_3J
Thu Nov 01, 2018 4:40 pm
Forum: Lewis Structures
Topic: Valence Electrons
Replies: 3
Views: 108

Re: Valence Electrons

A quick and easy way to find out how many valance electrons an element has is to count left to right across periods for the S orbital and the P orbital. For example H would have 1 valance electron, Be would have 2, B would have 3, and C would have 4. This would make the noble gases have 8 valence el...
by Javier_Ochoa_DIS_3J
Fri Oct 26, 2018 12:21 pm
Forum: Properties of Light
Topic: measuring wavelength
Replies: 5
Views: 136

Re: measuring wavelength

Anything below 10^-18 m is too small to measure.

However professor said that he will give either numbers that are super small or super big compared to 10^-18.
by Javier_Ochoa_DIS_3J
Fri Oct 26, 2018 12:19 pm
Forum: Properties of Light
Topic: The Uncertainty Principle
Replies: 2
Views: 114

Re: The Uncertainty Principle

1 joule = 1.60218e-19 Ev

It is given on the equation sheet in front of every test near the bottom.
by Javier_Ochoa_DIS_3J
Fri Oct 26, 2018 12:12 pm
Forum: Properties of Light
Topic: Power calculations
Replies: 6
Views: 239

Re: Power calculations

Make sure the use parentheses around your numbers.

For example instead of doing 9 x 10^3 times 3 x 10^2

You should input the numbers like this (9 x 10^3) times (3 x 10^2)

It is important when dividing and doing things other than just multiplying.
by Javier_Ochoa_DIS_3J
Fri Oct 19, 2018 4:00 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem Community Due Date
Replies: 6
Views: 168

Re: Chem Community Due Date

I don't believe there is a set date on the syllabus but I'd recommend getting it done by Sunday of that week?.
by Javier_Ochoa_DIS_3J
Fri Oct 19, 2018 3:57 pm
Forum: Quantum Numbers and The H-Atom
Topic: Equation sheet
Replies: 4
Views: 114

Re: Equation sheet

by Javier_Ochoa_DIS_3J
Fri Oct 19, 2018 3:54 pm
Forum: Properties of Light
Topic: energy equation
Replies: 4
Views: 66

Re: energy equation

The above poster is correct.

The equation you are looking for is E = hc/λ

λ = wave length
E = energy
h = Planck constant
c = speed of light

H and C will be provided in the information sheet in the test.
by Javier_Ochoa_DIS_3J
Fri Oct 19, 2018 12:47 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Clarification on Heisenberg Equation
Replies: 2
Views: 62

Re: Clarification on Heisenberg Equation

Hello, The way I understood it is that the reason this is true is because of how your TA stated when they said "by the time we calculate momentum, the object's position has already changed". What I took away from why this is, is because the more you investigate the position, the less you c...
by Javier_Ochoa_DIS_3J
Thu Oct 11, 2018 7:31 pm
Forum: SI Units, Unit Conversions
Topic: Units
Replies: 8
Views: 184

Re: Units

I'd also recommend putting the units as if it comes to partial credit for a question it might help who ever is grading it see what and where you went wrong. It could possibly improve your chances of getting more credit for a problem that would not have gotten it otherwise.
by Javier_Ochoa_DIS_3J
Thu Oct 11, 2018 7:27 pm
Forum: Empirical & Molecular Formulas
Topic: Rounding for limiting reactants
Replies: 5
Views: 151

Re: Rounding for limiting reactants

I see that your question has been pretty much answered but I'd recommend using the limiting rule of on no more than .1 to check your work. If it takes you more than a few calculation to get to a whole number of moles it is clear something went wrong. I tend to make a lot of little mistakes so it hel...
by Javier_Ochoa_DIS_3J
Sat Oct 06, 2018 1:45 pm
Forum: Administrative Questions and Class Announcements
Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sundays 4-6pm (Karen) [ENDORSED]
Replies: 135
Views: 28284

Re: DOWNLOAD SESSION WORKSHEETS HERE - Sundays 4-6pm (Karen) [ENDORSED]

This is perfect! I've been looking for more practice problems. Looking forward to the workshop.
by Javier_Ochoa_DIS_3J
Sat Oct 06, 2018 1:38 pm
Forum: SI Units, Unit Conversions
Topic: Formula Units?
Replies: 3
Views: 66

Re: Formula Units?

Formula units is the atoms I believe. First you have to get the moles of the element(s), To get this you have to use the given grams and divide it by the total molar mass found on the periodic table. You would multiply the moles with 6.0221409e+23 (Avogadro constant) to find out how many atoms or fo...
by Javier_Ochoa_DIS_3J
Sat Oct 06, 2018 1:35 pm
Forum: Significant Figures
Topic: Rounding numbers ending in 5
Replies: 9
Views: 130

Re: Rounding numbers ending in 5

I believe the text book is covering the rounding that is used in banking and possibly in chem labs, it makes the numbers more easier to work with.

You should keep rounding the way you have been taught.

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