Search found 19 matches

by Yizhou Liu 3L
Tue Dec 05, 2017 7:41 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted vs. Lewis
Replies: 4
Views: 233

Re: Bronsted vs. Lewis

The bronsted acid donates the H+; while the lewis acid accepts a lone pair.
by Yizhou Liu 3L
Tue Dec 05, 2017 7:36 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.29d
Replies: 2
Views: 161

Re: 12.29d

You need to use the formula M1V1=M2V2 to get the new concentration of KOH, which also equals to the concentration of OH- because KOH is a strong base.
by Yizhou Liu 3L
Tue Dec 05, 2017 7:32 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Weak Acids and Bases
Replies: 2
Views: 157

Re: Weak Acids and Bases

Strong acid or base can disassociate completely, which means there will only be one arrow toward the right.
by Yizhou Liu 3L
Sun Dec 03, 2017 3:30 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Why is Kw value typically used at 25 degrees C [ENDORSED]
Replies: 6
Views: 441

Re: Why is Kw value typically used at 25 degrees C [ENDORSED]

Because 25 degrees C is the room temperature. If the temperature increase, the Kw will increase as well.
by Yizhou Liu 3L
Sun Dec 03, 2017 3:25 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: 12.55 Part A
Replies: 2
Views: 222

Re: 12.55 Part A

I think you are talking about the Ka value for Ch3COOH. Those numbers are called acidity constants at 25 c, which are given on page 477 table 12.1.
by Yizhou Liu 3L
Mon Nov 27, 2017 8:14 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.14
Replies: 1
Views: 142

11.14

In question 11.14 it asks us to write the reaction quotient for NCl3(g) + 3H2O(l) ---- NH3(g) +3HOCl(aq). Should we calculate the kc or kp for this question?
by Yizhou Liu 3L
Mon Nov 27, 2017 8:08 am
Forum: Ideal Gases
Topic: Q and K [ENDORSED]
Replies: 35
Views: 1166

Re: Q and K [ENDORSED]

The formula of Q and K are the same, but they have different meanings.
by Yizhou Liu 3L
Fri Nov 17, 2017 6:06 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs Angular
Replies: 7
Views: 346

Re: Bent vs Angular

They're the same. They occur when lone pairs have more repulsive force than do shared electron pairs.
by Yizhou Liu 3L
Fri Nov 17, 2017 6:01 pm
Forum: Hybridization
Topic: Polar/nonpolar [ENDORSED]
Replies: 14
Views: 1425

Re: Polar/nonpolar [ENDORSED]

A polar molecule forms when an atom of high electronegativity bonds with a less electronegative atom. Conversely, the electrons of a non-polar molecule are distributed more equally.
by Yizhou Liu 3L
Sun Nov 05, 2017 4:46 pm
Forum: Lewis Structures
Topic: Cl as an Expanded Octet
Replies: 3
Views: 1019

Re: Cl as an Expanded Octet

ClO4^1- is a good example that Cl has expanded valence shell. If you put Cl as the central atom and connect it with O using single bond, you'll see the formal charge of Cl is +3 and O is -1. However, if you consider it as three double bonds and one single bond, the formal charge of Cl will be 0 and ...
by Yizhou Liu 3L
Sun Nov 05, 2017 4:35 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Lewis Structures and Formal Charge
Replies: 7
Views: 658

Re: Lewis Structures and Formal Charge

Not always. For those simple Lewis structures such as CH4 and NH3, we know that the formal charge would be 0 and there's only single bond in those molecules. However, for those exceptions to octet rule, such as SO4^2- and ClO4^1-, you need to calculate the formal charge because they have expanded va...
by Yizhou Liu 3L
Thu Oct 26, 2017 10:54 pm
Forum: Lewis Structures
Topic: Double or single bonds
Replies: 4
Views: 199

Re: Double or single bonds

When you draw a Lewis dot structure, you can either use two dots or a line between two atoms to represent a chemical bond. If there are two lines or four dots between two atoms, you'll know it's a double bond.
by Yizhou Liu 3L
Thu Oct 26, 2017 10:48 pm
Forum: Lewis Structures
Topic: Lewis Dot Structure Example
Replies: 3
Views: 106

Re: Lewis Dot Structure Example

Two (NH4)+ and one (SO4)2- can bond together by ionic bond and form (NH4)2SO4. When you draw the Lewis Dot structure, make sure to put the (NH4)+ on the left and (SO4)2- on the right.
by Yizhou Liu 3L
Thu Oct 19, 2017 12:30 pm
Forum: DeBroglie Equation
Topic: Can we use formula E=mv^2 to calculate the total energy?
Replies: 2
Views: 178

Can we use formula E=mv^2 to calculate the total energy?

We know that E=pv and p=mv, which means total energy should equal to mv^2. In the photoelectric experiment, we also know that E=work function+(mv^2)/2. However, work function doesn't equal to (mv^2/2), which means this equation is wrong. Does anyone know where I get wrong? Thank you.
by Yizhou Liu 3L
Thu Oct 19, 2017 12:12 pm
Forum: DeBroglie Equation
Topic: λ=c/v VS. λ=h/mv
Replies: 9
Views: 1253

Re: λ=c/v VS. λ=h/mv

In the equation λ=h/mv, v represents the velocity of any particle with momentum; while in the equation λ=c/v, c is a constant number represents the speed of light, which means this equation is only used for photon.
by Yizhou Liu 3L
Thu Oct 12, 2017 12:52 pm
Forum: Properties of Light
Topic: Clarification on C=λv
Replies: 10
Views: 1061

Re: Clarification on C=λv

When frequency decreases, wavelength will increase because the speed of light is constant.
by Yizhou Liu 3L
Wed Oct 11, 2017 2:29 pm
Forum: Properties of Light
Topic: Calculating the wavelength of light [ENDORSED]
Replies: 5
Views: 343

Re: Calculating the wavelength of light [ENDORSED]

First, you should remember the formula E=hv, where v stands for frequency and h is a constant number. Also, we know that ν = c/λ. If you plug ν = c/λ into the equation E=hv, you'll get E=hc/λ. In some questions they only give you the wavelength instead of the frequency, that's when you can apply thi...
by Yizhou Liu 3L
Thu Oct 05, 2017 7:36 am
Forum: Empirical & Molecular Formulas
Topic: F.23 Question [ENDORSED]
Replies: 5
Views: 420

Re: F.23 Question [ENDORSED]

Yes. Also, there's an easy way to do it. Each hydrocarbon in this problem has two carbons, which means the numerators are the same. So you can just compare the denominator by calculating the mass of H2,H2OH and H16.
by Yizhou Liu 3L
Thu Oct 05, 2017 7:20 am
Forum: Balancing Chemical Reactions
Topic: Nitrogen
Replies: 5
Views: 327

Re: Nitrogen

Yes. Nitrogen can only maintain in a liquid state at extremely low temperature or extremely high pressure. Its boiling point is 77K under atmospheric pressure, which means in most cases it is gaseous.

Go to advanced search