## Search found 16 matches

Thu Jan 18, 2018 6:11 pm
Forum: Phase Changes & Related Calculations
Topic: Self Test Example 8.1A
Replies: 1
Views: 162

### Self Test Example 8.1A

I saw this question under the self-test section of example 8.1 in the textbook and I'm a little confused on how we'd use both the densities of water and ice in this question. Water expands when it freezes. How much work does 100 g of water do when it freezes at 0.0 C and pushes back the metal wall ...
Sat Dec 09, 2017 3:00 pm
Forum: Electronegativity
Topic: Electron Affinity
Replies: 2
Views: 370

### Re: Electron Affinity

Chlorine does.
Sat Dec 09, 2017 2:59 pm
Forum: Properties of Light
Topic: Speed of light wavelength equation [ENDORSED]
Replies: 4
Views: 402

### Re: Speed of light wavelength equation[ENDORSED]

Sometimes you might also need to rearrange and plug this formula into a larger question/different formula. For example, you might rewrite E=hv to E=hc/lambda.
Fri Dec 08, 2017 11:33 pm
Forum: Biological Examples
Topic: Question on practice exam [ENDORSED]
Replies: 2
Views: 352

### Re: Question on practice exam[ENDORSED]

One oxygen molecule binds to each myoglobin.
Four oxygen molecules bind to each hemoglobin thus, I think four myoglobin would make up one hemoglobin. I'm not entirely sure though.
Fri Dec 08, 2017 11:19 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: X in ICE table
Replies: 3
Views: 284

### X in ICE table

I've heard there are some cases in which we can assume X i.e. the change between initial and final values in the table, is negligible. How do we identify when we can consider x negligible?
Fri Dec 08, 2017 11:16 pm
Forum: Bond Lengths & Energies
Topic: Bond Length and Bond Strength Relationship
Replies: 5
Views: 1257

### Bond Length and Bond Strength Relationship

I understand the relationship between bond length and bond strength but can someone explain to me the chemical reasoning behind why bond length affects bond strength?
Fri Dec 08, 2017 10:47 pm
Forum: Identifying Acidic & Basic Salts
Topic: Neutralization
Replies: 1
Views: 303

### Re: Neutralization

Neutralisation can occur between a strong base and a strong acid. With weak acids and strong bases, an equilibrium mixture is formed instead. Same with strong acids and weak bases. In a mixture of a weak base and a weak acid, complete neutralisation cannot occur.
Fri Dec 08, 2017 10:41 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Determining Denticity
Replies: 2
Views: 680

### Re: Determining Denticity

An easier way to look at this is to just keep an eye out for Ns and COOs. Count each of those as a possible binding site. A monodentate has one, bidentate has two etc.
For example:
NH3 is a monodentate.
(CH2N(CH2COO-)2)2 is a bidentate.
HN(CH2CH2CH(CH3)2 is a tridentate.
Fri Dec 08, 2017 10:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: CBr2Cl2
Replies: 2
Views: 386

### Re: CBr2Cl2

It's a polar compound as it is not symmetrical in shape and has polar bonds that do not cancel each other out. CBr2Cl2 is tetrahedral in shape. It has polar bonds in C-Br and C-Cl. Its shape is not symmetrical. Hence, it is a polar molecule. It appears to cancel each other out but does not when tran...
Fri Dec 08, 2017 10:21 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Pressure Effect
Replies: 3
Views: 287

### Re: Pressure Effect

When a system is at equilibrium and the pressure is increased, equilibrium shifts to the side with less particles. So if all three compounds were in their gaseous states, increasing pressure would cause equilibrium to shift to the left i.e. side with less moles of gas. If pressure was decreased, equ...
Fri Dec 08, 2017 10:14 pm
Forum: Amphoteric Compounds
Topic: Amphoteric vs amphiprotic
Replies: 1
Views: 305

### Re: Amphoteric vs amphiprotic

Both amphoteric and amphiprotic substances can act as acids and bases. It's just that one term, amphoteric refers to the whether the compound acts as an acid or base in a given medium and the other, amphiprotic, refers to a compound's ability to donate or accept a proton. Sometimes compounds are bot...
Fri Dec 08, 2017 10:08 pm
Forum: Hybridization
Topic: Chemical reasoning for hybridization
Replies: 2
Views: 250

### Re: Chemical reasoning for hybridization

As far as I'm aware, hybridization is more of a theoretical concept. It's supposed to explain certain structural issues that other bonding theories like VSEPR can't. Conceptually though, it's just different orbital interfering either constructively or destructively to give rise to equivalent orbital...
Sat Nov 04, 2017 10:29 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Aufbau principle
Replies: 4
Views: 401

### Re: Aufbau principle

As far as I'm aware, they're closely related and the Aufbau Principle originates from Pauli's exclusion principle. When we're writing out electronic configuration, I guess we just have to be mindful of all three.
Wed Oct 11, 2017 8:45 pm
Forum: Limiting Reactant Calculations
Topic: Net moles produced (Test question)
Replies: 3
Views: 360

### Re: Net moles produced (Test question)

I'm not entirely sure either but I think you're supposed to calculate the moles on the reactant side and the moles on the reactant side (using the limiting reagent) and find the difference between the two. Again, I'm not entirely clear on this either.
Mon Oct 02, 2017 11:54 pm
Forum: SI Units, Unit Conversions
Topic: Formula Units [ENDORSED]
Replies: 9
Views: 770

### Re: Formula Units[ENDORSED]

The simplest way to think about it, I think, is to just remember that formula units just refer to the number of moles x Avagadro's number. To obtain the number of moles, you'd just need to divide mass by molar mass, as was said previously.
Mon Oct 02, 2017 11:45 pm
Forum: Balancing Chemical Reactions
Topic: States of Matter in Chemical Equations
Replies: 4
Views: 436

### Re: States of Matter in Chemical Equations

I guess for now you might not be penalized but not writing out states might confuse you later on when writing equations for things like electrolysis where you might need to know the product formed or accumulating. It also helps for when you might need an understanding of the qualitative side of thin...