## Search found 20 matches

Fri Dec 08, 2017 1:14 am
Forum: Calculating the pH of Salt Solutions
Topic: pH of solutions not at 25 degrees C
Replies: 2
Views: 351

### Re: pH of solutions not at 25 degrees C

pH of water decreases as temperature increases. Although the pH of water changes with temperature, the acidity remains neutral. So the hydrogen ions and hydroxide ions remain the same numbers.
Fri Dec 08, 2017 1:08 am
Forum: Calculating the pH of Salt Solutions
Topic: Calculating pH
Replies: 3
Views: 324

### Re: Calculating pH

The negative logarithm is used so that most pH values are positive numbers.
Fri Dec 08, 2017 1:05 am
Forum: Calculating the pH of Salt Solutions
Topic: negative pH
Replies: 2
Views: 379

### Re: negative pH

Yes, Professor Lavelle told us during lecture that negative pH values are possible. Any acid that yields a concentration of hydrogen ions with a molarity greater than one will have a negative pH.
Fri Dec 08, 2017 1:00 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: pH in changing temperature
Replies: 4
Views: 479

### Re: pH in changing temperature

pH of pure water decreases as the temperature increases. Although the pH of pure water changes with temperature, it is important to realize that it is still neutral. In the case of pure water, there are going to be the same number of hydrogen ions and hydroxide ions.
Fri Dec 08, 2017 12:55 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka and Concentration
Replies: 3
Views: 397

### Re: Ka and Concentration

No. Ka, the acidity constant, is the products/reactants. Ka= [H30+][A-]/[HA].
Fri Dec 08, 2017 12:48 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Percent ionization
Replies: 3
Views: 294

### Re: Percent ionization

Yes. Percent deprotonation and percent ionization are the same. Deprotonation is an ionization method.
Fri Dec 08, 2017 12:39 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Relationship between Kpa and Ph
Replies: 3
Views: 432

### Re: Relationship between Kpa and Ph

pH of a solution is the negative logarithm of the hydronium ion activity. Ka is the acid ionization constant or acid dissociation constant. The weaker the acid is, which depends on the pH level, the smaller the value of Ka. Kb is the base ionization constant, and the smaller the value of Kb, the abi...
Fri Dec 08, 2017 12:18 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Difference between pH and pKa?
Replies: 4
Views: 479

### Re: Difference between pH and pKa?

pH is the hydronium ion concentration of the solution. The pH is the negative logarithm of the hydronium ion activity. pKa is the negative base -10 logarithm of the acid dissociation constant of a solution. The lower the pKa value, the stronger the acid.
Fri Dec 01, 2017 12:02 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Solids when using ICE [ENDORSED]
Replies: 8
Views: 1051

### Re: Solids when using ICE[ENDORSED]

Yes. You only use the concentrations of aqueous and gases in the ICE method. Therefore, you ignore the concentrations of the solids and liquids.
Thu Nov 30, 2017 11:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ch 11
Replies: 3
Views: 294

### Re: ch 11

You have to divide everything by .5 because the molarity is necessary. Molarity= moles/volume. In 11.33, the volume is .5 liters.
Tue Nov 21, 2017 5:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Why do lone pairs take up more space than bonds?
Replies: 5
Views: 6790

### Re: Why do lone pairs take up more space than bonds?

The lone pairs are localized around the central atom. The lone pairs occupy more space because there is greater repulsion with each other.
Tue Nov 21, 2017 5:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.25 (Polarity)
Replies: 4
Views: 335

### Re: 4.25 (Polarity)

The shape of the poly atomic molecule affects whether it is polar or not. First, draw the lewis structure. Then, use the VSEPR formula to name the molecular shape. Then you can identify the polarity by the dipoles. If the symmetry allows the dipoles to cancel, then the molecule is nonpolar. The mole...
Tue Nov 14, 2017 11:25 pm
Forum: Formal Charge and Oxidation Numbers
Topic: 3.49
Replies: 3
Views: 352

### Re: 3.49

The rest of your calculations are right except for the L in the formal charge equation. The L represents the actual number of lone pair electrons. So one lone pair would have 2 lone pair electrons. Therefore, the formal charge of Nitrogen= 5-(2+6/2). Formal charge of Oxygen= 6-(2+6/2).
Tue Nov 14, 2017 11:15 pm
Forum: Formal Charge and Oxidation Numbers
Topic: 3.49 (c) Oxygen's electrons
Replies: 3
Views: 385

### Re: 3.49 (c) Oxygen's electrons

The total valence electrons in the lewis structure are determined by adding up all the valence electrons. You have to satisfy the octet rule. You can do this by drawing bonds and lone pairs to get an accurate lewis structure.
Thu Nov 02, 2017 4:59 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: d and s blocks
Replies: 16
Views: 940

### Re: d and s blocks

I was confused by this at first too. The d block is listed first before the s block because the d block contains less energy than the s block. The principal quantum number "n" has more energy in comparison to "n-1." Therefore, the 3d would be written before 4s.
Thu Nov 02, 2017 4:45 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Homework Problem 2.55
Replies: 5
Views: 366

### Re: Homework Problem 2.55

I think the question is referring to the actual group 5 with transition elements such as V, Nb, Ta, and Db. In that case, the answer should be ns^2 (n-1)d^3. But the answer key says that ns^2 (n-1)d^5. Either the answer key is incorrect, or the question is actually referring to group 5 starting from...
Thu Oct 26, 2017 10:44 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Difference between subshell and orbital [ENDORSED]
Replies: 9
Views: 1570

### Re: Difference between subshell and orbital[ENDORSED]

Subshells are groups of orbitals that have the same value of l. For instance, there is only one subshell in the n=1 level (l=0).
Thu Oct 26, 2017 10:36 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Question on the difference between quantum numbers l and ml.
Replies: 3
Views: 346

### Re: Question on the difference between quantum numbers l and ml.

The quantum number l is the orbital angular momentum of the electron. It is the rate that the electron rotated round the nucleus and the shape. The magnetic quantum number ml specifies the orbitals of the subshell and the orientation.
Fri Oct 20, 2017 4:21 pm
Forum: DeBroglie Equation
Topic: 1.39 Help
Replies: 5
Views: 378

### Re: 1.39 Help

First convert the mass into kilograms and the velocity into ms^-1. You placed the numbers correctly into the equation, but the only thing you are missing is the 41ms^-1.
Fri Oct 20, 2017 4:10 pm
Forum: Properties of Light
Topic: test 2 topic
Replies: 9
Views: 730

### Re: test 2 topic

Usually if the idea isn't mentioned at all in the homework, I would say don't focus your time too much on it. I assume Dr. Lavelle did not go over information in section 1.1 because the information is basic and general in comparison to the formulas or other concepts. I usually just study the homewor...

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