## Search found 28 matches

Sat Dec 03, 2016 8:50 am
Forum: Calculating the pH of Salt Solutions
Topic: Strength of Acids/Bases
Replies: 1
Views: 413

### Re: Strength of Acids/Bases

The larger the kB, the more the compound will dissociate and form product since kB= [products]/ [reactants], therefore, the stronger the base. The larger the kA, the more the compound will dissociate and form product, therefore, the stronger the acid.
Tue Nov 29, 2016 4:38 pm
Forum: *Titrations & Titration Calculations
Topic: Chapter 13 Problem 3
Replies: 1
Views: 469

### Chapter 13 Problem 3

Here is the question- A solution of equal concentrations of glyceric acid and sodium glycerate was found to have pH= 3.52. (a) What are pKa and Ka for glyceric acid? (b) What would the pH be if the concentration of acid was twice that of the salt? The solution uses the ice chart in order to find the...
Mon Nov 28, 2016 8:52 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Chapter 12 Problem 117
Replies: 1
Views: 320

### Chapter 12 Problem 117

Here is the problem- Write the equilibrium constant for the following reaction and calculate the value of K at 298 K for the reaction HNO_{2} (aq) + NH_{3} (aq)\rightleftharpoons NH_{4}^{+} (aq) +NO_{2}^{-}(aq) using the data in Tables 12.1 and 12.2. Why does the solu...
Mon Nov 21, 2016 8:09 am
Forum: Conjugate Acids & Bases
Topic: What does a conjugate acid/base do? [ENDORSED]
Replies: 4
Views: 900

### Re: What does a conjugate acid/base do?[ENDORSED]

The conjugate base is the compound formed once the acid donates a proton. A conjugate acid would be formed when a base accepts a proton.
Mon Nov 14, 2016 8:27 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Naming Chemical Compounds
Replies: 2
Views: 361

### Re: Naming Chemical Compounds

You can determine the coordination number by determining the number of bonds between the transition metal and the ligands. For naming chemical compounds, first you list the ligands in alphabetical order, using prefixes if there are more than 1 of the ligand, and then list the transition metal with i...
Mon Nov 14, 2016 8:22 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Does hydrate (the H2O attached after one complex) count when counting the coordination number of the central metal ?
Replies: 1
Views: 212

### Re: Does hydrate (the H2O attached after one complex) count when counting the coordination number of the central metal ?

No, it is not counted when counting the coordination number. The water is just surrounding the coordination compound. Since it is not bonded to the transition metal, it is not counted in the coordination number.
Sun Nov 13, 2016 9:00 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Wrting the Chemical Formula for Coordination Compounds
Replies: 3
Views: 1547

### Wrting the Chemical Formula for Coordination Compounds

When writing the chemical formula for coordination compounds, how should you determine what order to write the molecules in? Is there a rule to follow for writing chemical formulas for coordination compounds?
Sat Nov 12, 2016 12:42 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Chapter 4 Problem 51
Replies: 1
Views: 263

### Chapter 4 Problem 51

Here is the problem- Draw a molecular orbital energy level diagram and determine the bond order expected for each of the following diatomic species: (a) Li_{2} ; (b) Li_{2}^{+} ; (c) Li_{2}^{-} . State whether each molecule or ion will be paramagnetic or diamagnetic. If it is paramagnetic, give the ...
Fri Nov 11, 2016 10:23 am
Forum: Naming
Topic: Chapter 17 Problem 31
Replies: 1
Views: 245

### Chapter 17 Problem 31

Here is the problem- Use the information in Table 17.4 to write the formula for each of the following coordination compounds (a) potassium hexacyanidochromate (lll) (b) pentaamminesulfatocobalt (lll) chloride (c) tetraamminediaquacobalt (lll) bromide (d) sodium bisoxalato(diaqua) ferrate (lll) Why i...
Mon Nov 07, 2016 8:27 am
Forum: Ionic & Covalent Bonds
Topic: ionic vs. covalent bonds
Replies: 2
Views: 398

### Re: ionic vs. covalent bonds

Ionic bonds can have some covalent character and covalent bonds can have some ionic character. This is why the bonds are mostly ionic if the electronegativity difference is greater than 2 and mostly covalent if the electronegativity difference is less than 1.5. If the electronegativity difference be...
Mon Oct 31, 2016 8:57 am
Forum: Dipole Moments
Topic: Polarity
Replies: 5
Views: 512

### Polarity

How do you determine polarity of a molecule? Do you have to draw the molecule according to its shape in order to determine polarity, or is just drawing the lewis structure sufficient to determine the dipole moments and polarity?
Mon Oct 31, 2016 8:49 am
Forum: Bond Lengths & Energies
Topic: Bond Dissociation
Replies: 1
Views: 434

### Re: Bond Dissociation

The lone pairs repel each other since they both have negative charges since they are electrons. A triple bond will be harder to break since it is a shorter bond and the atoms are held more tightly together. Therefore, it has a higher dissociation energy. A single bond will be easier to break since i...
Sun Oct 30, 2016 8:26 am
Forum: Lewis Structures
Topic: Chapter 4 Question 99
Replies: 1
Views: 292

### Chapter 4 Question 99

I am having trouble with drawing the lewis structure of [Bi_{2}Cl_{4}]^{2-} . Here is the problem- Just as AlCl_{3} forms dimers (Section 3.11), in the [Bi_{2}Cl_{4}]^{2-} ion two of the Cl atoms form bridges between the two Bi atoms. Propose a structure for the [Bi_{2}Cl_{4}]^{2-} ions. Why do you ...
Tue Oct 25, 2016 4:34 pm
Forum: Lewis Structures
Topic: CO Lewis structure
Replies: 1
Views: 241

### Re: CO Lewis structure

The structure with lower formal charges is more favorable, so the best structure will have the lowest formal charge.
Mon Oct 24, 2016 8:39 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Cation and Anions [ENDORSED]
Replies: 1
Views: 351

### Re: Cation and Anions[ENDORSED]

Cations are smaller than their parent ions since an electron is removed to form the cation. Because electrons primarily make up the volume of an atom, the cation will be smaller since it has fewer electrons. Anions are larger than their parent atoms because an electron is gained to form an anion, th...
Mon Oct 24, 2016 8:36 am
Forum: Lewis Structures
Topic: Question 61 Chapter 3
Replies: 1
Views: 234

### Question 61 Chapter 3

Here is the problem- Determine the numbers of electron pairs (both bonding and lone pairs) on the iodine atom in (a) ICl_{2}^{+} ; (b) ICl_{4}^{-} (c) ICl_{3} ; (d) ICl_{5} . I was having trouble with drawing the lewis structure for ICl_{4}^{-} . Why is the structure drawn with two of the chlorine a...
Mon Oct 17, 2016 5:09 pm
Forum: Formal Charge and Oxidation Numbers
Topic: SO4^2- Lewis Structure [ENDORSED]
Replies: 1
Views: 524

### Re: SO4^2- Lewis Structure[ENDORSED]

On the sulfur atom in the resonance structure which is the best representation of sulfate, there are 12 electrons. Sulfur is able to have an expanded octet since it can have s,p, and d orbitals. This means that there are 2 electrons in the 3s orbital, 6 electrons in the 3 p orbital, and 4 electrons ...
Mon Oct 17, 2016 5:05 pm
Forum: Resonance Structures
Topic: Resonance and Energy [ENDORSED]
Replies: 2
Views: 388

### Re: Resonance and Energy[ENDORSED]

Resonance lowers a molecule's energy because there are delocalized electrons in resonance structures.
Mon Oct 10, 2016 5:35 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Emission v Absorption Lines
Replies: 2
Views: 408

### Re: Emission v Absorption Lines

The lines on an emission spectrum indicate the wavelengths of light that a substance can emit. The lines on an absorption spectrum indicate the wavelengths of light that a substance can absorb.
Mon Oct 10, 2016 5:31 pm
Forum: Empirical & Molecular Formulas
Topic: Writing Chemical Formulas
Replies: 1
Views: 283

### Writing Chemical Formulas

How do you determine which order you should write elements in a chemical formula? For example, how would you know carbon comes first, then hydrogen in $CH_{4}$? Is there any trend or rule for writing chemical formulas to determine the order of the elements in the chemical formula?
Fri Oct 07, 2016 12:59 pm
Forum: Quantum Numbers and The H-Atom
Topic: Magnetic Quantum Number [ENDORSED]
Replies: 2
Views: 534

### Magnetic Quantum Number[ENDORSED]

How can you determine the number of magnetic quantum numbers possible from the value of the angular momentum quantum number? For example, How would you know that when l=1, the magnetic quantum number can have three possible values ,-1,0,1?
Mon Oct 03, 2016 5:18 pm
Forum: Photoelectric Effect
Topic: Photoelectric effect [ENDORSED]
Replies: 2
Views: 290

### Re: Photoelectric effect[ENDORSED]

The energy of the photon that is emitted will be equal to the energy of the light that excited the electron because of conservation of energy. The energy of the incoming light is equal to the energy difference between energy levels. That energy difference is then equal to the energy of the electroma...
Sun Oct 02, 2016 9:08 am
Forum: Photoelectric Effect
Topic: Question 18 Part B on Photoelectric Post Assessment [ENDORSED]
Replies: 3
Views: 535

### Re: Question 18 Part B on Photoelectric Post Assessment[ENDORSED]

Sat Oct 01, 2016 3:58 pm
Forum: Photoelectric Effect
Topic: Question 18 Part B on Photoelectric Post Assessment [ENDORSED]
Replies: 3
Views: 535

### Question 18 Part B on Photoelectric Post Assessment[ENDORSED]

How do you begin to solve part b of question 18 on the photoelectric post assessment? Here is the question- Light hits a sodium metal surface and the velocity of the ejected electron is 6.61x10^{5}m.s^{-1} . The work function for sodium is 150.6 kJ.mol^{-1} . How much energy is required to remove an...
Thu Sep 29, 2016 9:07 pm
Forum: Photoelectric Effect
Topic: Photoelectric effect- how is it detected?
Replies: 1
Views: 280

### Re: Photoelectric effect- how is it detected?

In the photoelectric effect, the electrons are detected by a detector. The electrons will not be detected visibly in the form of light in the photoelectric effect. In atomic spectroscopy, electrons are excited to a higher energy level and when they return back to the original energy level, they emit...
Mon Sep 26, 2016 9:39 am
Forum: SI Units, Unit Conversions
Replies: 2
Views: 340

### Re: Significant Figures in Answer

If you are multiplying or dividing in the problem, the answer should have the same number of significant figures as the given value. In this case, the number of significant figures would be four. If you are adding or subtracting in the problem, the answer should contain the same number of decimal pl...
Sun Sep 25, 2016 11:28 am
Forum: Administrative Questions and Class Announcements
Topic: Homework Assignment?
Replies: 7
Views: 808

### Re: Homework Assignment?

Dr. Lavelle is referring to the homework problems listed in the beginning of the course reader. M21 is problem number 21 in Fundamentals Section M in the textbook.
Sat Sep 24, 2016 2:04 pm
Forum: Limiting Reactant Calculations
Topic: Fundamentals M11
Replies: 1
Views: 304

### Fundamentals M11

Here is the question from the textbook (Fundamentals Section M)- A reaction vessel contains 5.77 g of white phosphorus and 5.77 g of oxygen. The first reaction to take place is the formation of phosphorus (lll) oxide, P_{4}O_{6} : P_{4} (s) +3O_{2} (g)\rightarrow P_{4}O_{6} (s...