## Search found 20 matches

Sat Dec 09, 2017 2:55 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: q65 writing the pH and writing equations to support it [ENDORSED]
Replies: 1
Views: 228

### q65 writing the pH and writing equations to support it[ENDORSED]

For KBr, why is it neutral? and for AlCl3, why is it Al(H2O)6 3+ and not cl3-?
Sat Dec 09, 2017 1:43 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.55 (c) increasing acidity
Replies: 2
Views: 236

### Re: 12.55 (c) increasing acidity

Oh, sorry i should've written the question out - it asks to explain it in terms of structure.
Sat Dec 09, 2017 12:33 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.55 (c) increasing acidity
Replies: 2
Views: 236

### 12.55 (c) increasing acidity

Why is HCOOH more acidic than CH3COOH?
Tue Dec 05, 2017 10:54 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: J.5 Problem
Replies: 3
Views: 335

### Re: J.5 Problem

The question also writes "If the substance is a weak acid or base, leave it in its molecular form in the equations" and thus since HF is weak, you don't write it as its ions.
Fri Dec 01, 2017 11:17 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 11.89 part b
Replies: 2
Views: 277

### 11.89 part b

I'm not sure what im missing, but for qn 11.89b, it asks for the equilibrium constant. What i'm confused about is why they divide the values by 100.
Wed Nov 29, 2017 3:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Basic Bond Angles [ENDORSED]
Replies: 1
Views: 197

### Basic Bond Angles[ENDORSED]

What basic bond angles are we expected to know?
Mon Nov 20, 2017 2:13 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Drawing Shape
Replies: 1
Views: 155

### Drawing Shape

Hi, When drawing the shape of a molecule do we need to draw the 3d shape? ie the triangles and stuff
Thu Nov 09, 2017 4:02 pm
Forum: Lewis Structures
Topic: double bonds in NO3-
Replies: 2
Views: 643

### double bonds in NO3-

Hi, for the structure of NO3- there is one double bond bet. N-O, my question is why aren't they all double bonds? ie 3 double bonds.
Wed Nov 08, 2017 4:21 pm
Forum: Lewis Structures
Topic: where do you place the unpaired electron of a free radical?
Replies: 2
Views: 320

### where do you place the unpaired electron of a free radical?

How do you know which atom the unpaired electron goes to? e.g. ClO in 3.57 - why is the unpaired electron on Cl and not on O?
Wed Nov 08, 2017 3:00 pm
Forum: Resonance Structures
Topic: 3.57 hydrogen sulfite
Replies: 1
Views: 214

### 3.57 hydrogen sulfite

Hi, for chp 3 q 57b, i was wondering why the H in the lewis structure is connected to the O atom and not the S atom?
Wed Nov 08, 2017 2:49 pm
Forum: Resonance Structures
Topic: double headed arrow for resonance [ENDORSED]
Replies: 1
Views: 243

### double headed arrow for resonance[ENDORSED]

When are we supposed to draw the double headed arrow when drawing lewis structures? is it whenever the you draw more than one structure? im confused because in the textbook solutions they dont always draw arrows
Wed Nov 08, 2017 9:46 am
Forum: Lewis Structures
Topic: Lewis Acids and Bases
Replies: 2
Views: 210

### Lewis Acids and Bases

Hi, in the chapter summery for chemical bonds, prof lavelle wrote "Explain the characteristics of Lewis acids and bases and how they form coordinate
covalent bonds." Does anyone know the answer to this?
Fri Nov 03, 2017 11:48 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Homework Problem 2.55
Replies: 5
Views: 392

### Re: Homework Problem 2.55

I also do not understand why for the group 15 elements, there is no (n-1)d^10 but is just ns^2np^3
Tue Oct 31, 2017 6:37 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Chapter 1 #57 [ENDORSED]
Replies: 2
Views: 436

### Re: Chapter 1 #57[ENDORSED]

Just to clarify though - in the solutions manual they say that n2 = 7. The values given are 656.3, 486.1, 434.0, and 410.2 nm. Does that mean that 656.3 is 3, 486.1 is 4, 434 is 5, 410.2 is 6? ie that the lines don't start at the second but at the third energy level?
Fri Oct 27, 2017 9:42 pm
Forum: Resonance Structures
Topic: Resonance in SO4
Replies: 5
Views: 487

### Re: Resonance in SO4

So the most important thing is to make sure the FC of the central atom is as close to 0 as possible?
Fri Oct 27, 2017 2:26 pm
Forum: Resonance Structures
Topic: Resonance in SO4
Replies: 5
Views: 487

### Resonance in SO4

Hi, Today in class we learnt that the resonant structure of SO4 (2-) is when S has 2 double bonds and 2 single bonds, calculated using the formal charge. Why isnt having 4 double bonds more stable since the FC will be 0 for all of the O atoms?
Thu Oct 19, 2017 11:46 am
Forum: Photoelectric Effect
Topic: Finding the number of photons
Replies: 2
Views: 1032

### Finding the number of photons

In the post-module assessment there is the following question: In 1.0 s, a 60 W bulb emits 11 J of energy in the form of infrared radiation (heat) of wavelength 1850 nm. What is the energy per photon of light emitted? How many photons of infrared radiation does the lamp generate in 1.0 s? How do you...
Mon Oct 16, 2017 11:13 pm
Forum: Administrative Questions and Class Announcements
Topic: Has the location of the UA Peer Learning on Monday at Young Hall 4222 changed? [ENDORSED]
Replies: 1
Views: 230

### Has the location of the UA Peer Learning on Monday at Young Hall 4222 changed?[ENDORSED]

Me and a couple of students went to the 4222 Young Hall for the peer learning sessions and were there from 1-4pm and there were no UAs conducting peer learning sessions and so i was wondering, has the location changed?
Fri Oct 13, 2017 1:15 am
Forum: Balancing Chemical Reactions
Topic: Combustion Question
Replies: 9
Views: 778

### Re: Combustion Question

One thing to note though, is that the resulting water is actually water vapor, which previous replies have stated but i just wanted to make it clear. Thus both products, CO2 and H2O are in gaseous states
Fri Oct 13, 2017 1:12 am
Forum: Limiting Reactant Calculations
Topic: volume of stock solution needed to make 250ml of 0.650M NaOH
Replies: 1
Views: 1081

### volume of stock solution needed to make 250ml of 0.650M NaOH

In the test, the question asks for the volume needed to make a 250 ml 0.60 M NaOH solution and i dont quite understand what is meant by stock solution because in the previous questions they aked how may grams of NaOH do you need to prepare a 3.00x10^2 ml stock solution so i understood the stock solu...