Search found 19 matches
- Tue Dec 05, 2017 7:41 pm
- Forum: Bronsted Acids & Bases
- Topic: Bronsted vs. Lewis
- Replies: 4
- Views: 614
Re: Bronsted vs. Lewis
The bronsted acid donates the H+; while the lewis acid accepts a lone pair.
- Tue Dec 05, 2017 7:36 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: 12.29d
- Replies: 4
- Views: 1115
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.
- Tue Dec 05, 2017 7:32 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Weak Acids and Bases
- Replies: 2
- Views: 477
Re: Weak Acids and Bases
Strong acid or base can disassociate completely, which means there will only be one arrow toward the right.
- 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: 2111
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.
- Sun Dec 03, 2017 3:25 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: 12.55 Part A
- Replies: 2
- Views: 544
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.
- Mon Nov 27, 2017 8:14 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 11.14
- Replies: 1
- Views: 357
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?
- Mon Nov 27, 2017 8:08 am
- Forum: Ideal Gases
- Topic: Q and K [ENDORSED]
- Replies: 35
- Views: 3240
Re: Q and K [ENDORSED]
The formula of Q and K are the same, but they have different meanings.
- Fri Nov 17, 2017 6:06 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent vs Angular
- Replies: 7
- Views: 805
Re: Bent vs Angular
They're the same. They occur when lone pairs have more repulsive force than do shared electron pairs.
- Fri Nov 17, 2017 6:01 pm
- Forum: Hybridization
- Topic: Polar/nonpolar [ENDORSED]
- Replies: 14
- Views: 2716
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.
- Sun Nov 05, 2017 4:46 pm
- Forum: Lewis Structures
- Topic: Cl as an Expanded Octet
- Replies: 3
- Views: 5803
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 ...
- Sun Nov 05, 2017 4:35 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Lewis Structures and Formal Charge
- Replies: 7
- Views: 1435
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...
- Thu Oct 26, 2017 10:54 pm
- Forum: Lewis Structures
- Topic: Double or single bonds
- Replies: 4
- Views: 530
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.
- Thu Oct 26, 2017 10:48 pm
- Forum: Lewis Structures
- Topic: Lewis Dot Structure Example
- Replies: 3
- Views: 1007
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.
- 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: 519
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.
- Thu Oct 19, 2017 12:12 pm
- Forum: DeBroglie Equation
- Topic: λ=c/v VS. λ=h/mv
- Replies: 9
- Views: 13160
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.
- Thu Oct 12, 2017 12:52 pm
- Forum: Properties of Light
- Topic: Clarification on C=λv
- Replies: 10
- Views: 4327
Re: Clarification on C=λv
When frequency decreases, wavelength will increase because the speed of light is constant.
- Wed Oct 11, 2017 2:29 pm
- Forum: Properties of Light
- Topic: Calculating the wavelength of light [ENDORSED]
- Replies: 5
- Views: 1007
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...
- Thu Oct 05, 2017 7:36 am
- Forum: Empirical & Molecular Formulas
- Topic: F.23 Question [ENDORSED]
- Replies: 5
- Views: 1172
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.
- Thu Oct 05, 2017 7:20 am
- Forum: Balancing Chemical Reactions
- Topic: Nitrogen
- Replies: 5
- Views: 748
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.