## Search found 25 matches

Fri Dec 08, 2017 1:09 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.55 a
Replies: 1
Views: 136

### 12.55 a

Calculate the pH, pOH, and percentage deprotonation of each of the following aqueous solutions: (a) 0.20 m CH3COOH(aq); (b) 0.20 m CCl3COOH(aq); (c) 0.20 m HCOOH(aq). (d) Explain any differences in pH on the basis of molecular structure. How do you calculate Ka for part a when you are only given 0.2...
Thu Dec 07, 2017 11:53 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.27
Replies: 1
Views: 157

### 12.27

A careless laboratory technician wants to prepare 200.0 mL of a 0.025 M HCl(aq) solution, but uses a 250.0-mL volumetric ask by mistake. (a) What would the pH of the desired solution have been? (b) What will be the actual pH of the solution as prepared? For part b, why do we continue to use the mola...
Thu Dec 07, 2017 11:03 pm
Forum: Lewis Acids & Bases
Topic: 12.17
Replies: 2
Views: 191

### 12.17

State whether the following oxides are acidic, basic, or amphoteric: (a) BaO; (b) SO3; (c) As2O3; (d) Bi2O3.

Would the only approach to this be drawing the Lewis structures? Thanks!
Thu Dec 07, 2017 12:55 pm
Forum: Conjugate Acids & Bases
Topic: 12.9 C
Replies: 1
Views: 158

### 12.9 C

Why is there no proton transfer in part c) CH3COOH(aq)+ NH3(aq) -> CH3CONH2(aq)+ H2O(l) ? Thanks!
Thu Dec 07, 2017 12:35 pm
Forum: Conjugate Acids & Bases
Topic: HW 12.3
Replies: 3
Views: 212

### Re: HW 12.3

SO4 2- is the conjugate base of HSO4- because, as stated above, the difference is only a single hydrogen. When finding the conjugate base of something, remove a single hydrogen and add a negative charge, hope this helps!
Thu Dec 07, 2017 1:34 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 11.79
Replies: 1
Views: 169

### 11.79

A reactor for the production of ammonia by the Haber process is found to be at equilibrium with PN2 3.11 bar, PH2 1.64 bar, and PNH3 23.72 bar. If the partial pressure of N2 is increased by 1.57 bar, what will be the partial pressure of each gas once equilibrium is re-established? I followed the sol...
Wed Dec 06, 2017 9:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.45
Replies: 1
Views: 172

### 11.45

a) A sample of 2.0 mmol Cl2(g) was sealed into a 2.0-L reaction vessel and heated to 1000. K to study its dissociation into Cl atoms. Use the information in Table 11.2 to calculate the equilibrium composition of the mixture. (b) If 2.0 mmol F2 was placed into the reaction vessel instead of the chlor...
Tue Nov 28, 2017 11:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Square planar vs Tetrahedral
Replies: 2
Views: 193

### Square planar vs Tetrahedral

How can you differentiate between a square planar shape and a tetrahedral shape when looking at Lewis dot structures? Thanks!
Tue Nov 28, 2017 8:31 pm
Forum: Hybridization
Topic: 4.43
Replies: 2
Views: 231

### 4.43

Noting that the bond angle of an sp3 hybridized atom
is 109.5 and that of an sp2 hybridized atom is 120 , do you expect the bond angle between two hybrid orbitals to increase or decrease as the s-character of the hybrids is increased?

What do they mean when they say s-character? Thanks!
Tue Nov 28, 2017 12:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.19 b
Replies: 3
Views: 191

### 4.19 b

Why is the shape of (CH3)2Be tetrahedral? With Be as the central atom, there's only two regions of electron density. Can someone please explain how it ends up being a tetrahedral? Thanks!
Mon Nov 27, 2017 9:46 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Chemical Equilibrium 1A Post Module 31
Replies: 1
Views: 128

### Chemical Equilibrium 1A Post Module 31

With respect to equilibrium constants what does it mean when the “equilibrium is shifted to the left”?

Also the module asks two different questions, one with "shifted to the left" and "lies to the left". Is there any difference between the two phrases? Thanks!
Mon Nov 27, 2017 10:38 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pair Effect on Bond Angles [ENDORSED]
Replies: 3
Views: 360

### Lone Pair Effect on Bond Angles[ENDORSED]

How do lone pairs affect the standard bond angles for each shape? If a lone pair does exist, to what extent does it affect the bond angle and is there any way to calculate this?
Mon Nov 27, 2017 10:35 am
Forum: Naming
Topic: Oxidation Number [ENDORSED]
Replies: 1
Views: 174

### Re: Oxidation Number[ENDORSED]

The oxidation number is the overall charge of the compound. You would add up all the charges of the compound and the sum would be the oxidation number, or the charge of the compound.
Thu Nov 09, 2017 1:31 am
Forum: Trends in The Periodic Table
Topic: s-block vs p-block
Replies: 5
Views: 777

### s-block vs p-block

Why are s-block metals typically more reactive than p-block metals?
Wed Nov 08, 2017 6:12 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Unpaired Electrons [ENDORSED]
Replies: 7
Views: 407

### Unpaired Electrons[ENDORSED]

How do you determine the number of unpaired electrons from looking at the ground state configuration? Thanks!
Thu Nov 02, 2017 12:51 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: d orbital or s orbital first?
Replies: 5
Views: 307

### d orbital or s orbital first?

When do you know when to begin the electron configuration with the d orbital instead of the s orbital first?
Mon Oct 30, 2017 5:07 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Exercise 1.45
Replies: 4
Views: 293

### Re: Exercise 1.45

This does not answer your question regarding the +/- but the solutions manual states 5.0 m/s-1 as delta v, but delta v should actually be 10 m/s-1. It is simply an error and can be found in the Solutions Manual Errors link on the class website. It should clear up any confusion when it comes to deter...
Thu Oct 26, 2017 1:19 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: s- electrons vs p- electrons [ENDORSED]
Replies: 7
Views: 483

### s- electrons vs p- electrons[ENDORSED]

Can someone explain to me why s- electrons have lower energy than p-electrons in the same shell? Thanks!
Thu Oct 26, 2017 1:06 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Ground or Excited State?
Replies: 2
Views: 198

### Ground or Excited State?

How do you determine if an electron configuration represents the ground state or the excited state of the atom given?
Thu Oct 19, 2017 11:00 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Chapter 1 #55
Replies: 1
Views: 167

### Chapter 1 #55

Infrared spectroscopy is an important tool for studying vibrations of molecules. Just as an atom can absorb a photon of suitable energy to move an electron from one electronic state to another, a molecule can absorb a photon of electromagnetic radiation in the infrared region to move from one vibrat...
Thu Oct 19, 2017 10:40 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Chapter 1 #43 [ENDORSED]
Replies: 7
Views: 445

### Chapter 1 #43[ENDORSED]

What is the minimum uncertainty in the speed of an electron con ned to within a lead atom of diameter 350. pm? Model the atom as a one-dimensional box with a length equal to the diameter of the actual atom. What does this question ask for specifically when it says to model the atom as a one-dimensio...
Thu Oct 12, 2017 9:46 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7742
Views: 1060621

### Re: Post All Chemistry Jokes Here

Did you hear about Oxygen and Magnesiym getting together?
I was like OMg!!!
Thu Oct 12, 2017 9:45 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7742
Views: 1060621

### Re: Post All Chemistry Jokes Here

Argon is tending the bar. Helium walks in.
Neither react.
Thu Oct 05, 2017 11:28 am
Forum: Empirical & Molecular Formulas
Topic: E29 Fundamentals
Replies: 3
Views: 231

### E29 Fundamentals

A chemist measured out 8.61 g of copper(II) chloride tetrahydrate, CuCl2 4H2O. (a) How many moles of CuCl2 4H2O were measured out? (b) How many moles of Cl ions are present in the sample? (c) How many H2O molecules are present in the sample? (d) What fraction of the total mass of the sample was due ...
Thu Oct 05, 2017 12:40 am
Forum: Molarity, Solutions, Dilutions
Topic: G11
Replies: 2
Views: 200

### G11

TA medical researcher investigating the properties of intravenous solutions prepared a solution containing 0.278 m C6H12O6 (glucose). What volume of solution should the researcher use to provide 4.50 mmol C6H12O6? Can someone explain how to begin this problem? I do not know how to approach it withou...