Search found 22 matches

Tue Aug 01, 2017 7:41 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.67
Replies: 1
Views: 392

12.67

Rank solutions in order of increasing pH:

a)1.0x10^-5M HCl (aq)
b)0.20M CH3NH3Cl (aq)
c)0.20M CH3COOH (aq)
d)0.20M C6H5NH2 (aq)

I noticed that there were no calculations done in the solution manual, so is this solely based on the properties of weak acids/bases and strong acids/bases?
Sun Jul 30, 2017 11:40 pm
Forum: Conjugate Acids & Bases
Topic: 12.1
Replies: 4
Views: 462

Re: 12.1

Also, in part f) CH3COOH, does the O2 in the answer represent the two O at. the end of the compound after hydrogen is removed? I hope my question makes sense lol
Sun Jul 30, 2017 11:37 pm
Forum: Conjugate Acids & Bases
Topic: 12.1
Replies: 4
Views: 462

12.1

I am a bit confused about writing the formulas of conjugate bases, in terms of what happens to hydrogen. In part d) we are given HCO3-, but then when we write the conjugate the hydrogen disappears. Is it because it is being added to the other side, causing the charge to change to 2-?
Sun Jul 30, 2017 11:21 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.55
Replies: 1
Views: 290

12.55

Calculate the pH, pOH, and percentage deprotonation of each of the following aqueous solutions:
a) 0.20M CH3COOH(aq)

Can someone help me out please?
Sun Jul 30, 2017 2:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.45 Part C
Replies: 3
Views: 326

11.45 Part C

C) Use your results from parts a and b to determine which is thermodynamically more stable relative to its atoms at 1000 K, Cl2 or F2. Results: Cl2= .001mol/L; 2Cl=1.1x10^-5mol/L F2=8.4x10^-3mol/L; 2F=3.2x10^-3mol/L How exactly do we know which one is the most stable based on these results?
Sun Jul 23, 2017 11:35 pm
Forum: Naming
Topic: H20
Replies: 1
Views: 220

H20

Does it make a difference how we write h20 when we are naming coordination compounds? I have noticed that sometimes it is written as h20 and other times it's oh2.
Sun Jul 23, 2017 11:28 pm
Forum: Naming
Topic: HW Question 17.31
Replies: 4
Views: 446

Re: HW Question 17.31

For part b of this question, which is pentaamminesulfatocobalt (III) chloride, how do we find the number of chlorines needed?
Sun Jul 23, 2017 8:34 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Chemical Equilibrium Post Assessment 3
Replies: 1
Views: 318

Chemical Equilibrium Post Assessment 3

16. 0.482 mol N2 and 0.933 mol O2 are placed in a 10.0 L reaction vessel and form N2O (dinitrogen oxide): 2N2(g) + O2(g) ⇌ 2N2O(g) KC = 2.0 x 10-37 What is the composition of the equilibrium mixture? A. [N2] = 0.0482 mol.L-1; [O2] = 0.0933 mol.L-1; [N2O] = 6.6 x 10-21 mol.L-1 B. [N2] = 0.0933 mol.L-...
Sat Jul 22, 2017 5:35 pm
Forum: Lewis Structures
Topic: Problem 3.45
Replies: 2
Views: 279

Problem 3.45

Draw the Lewis structures that contribute to the resonance hybrid of nytril chloride.

In the answer, it shows that the oxygens are perpendicular to each other. Would it be wrong to draw it with the oxygens being straight across from each other?
Sat Jul 22, 2017 5:08 pm
Forum: Lewis Structures
Topic: Tips for completing Lewis Structures
Replies: 4
Views: 384

Tips for completing Lewis Structures

Do any of you have any tips for drawing Lewis structures, particularly for more complex compounds such as glycine (chapter 3, question 41). The Lewis structure makes sense when looking at the answer but I want to know what steps they took to arrive at that answer. Hope you can help!
Sun Jul 16, 2017 11:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Strength of Repulsion
Replies: 1
Views: 726

Strength of Repulsion

Can someone explain why lone-lone pairs have a higher strength of repulsion than a lone-bonding pair or a bonding-bonding pair?
Sun Jul 16, 2017 10:48 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charges
Replies: 1
Views: 233

Formal Charges

If the most stable formal charge is 0, what does that mean for other charges? Is a +1charge more stable than a -1 charge? Hope someone can help me out, thanks!
Tue Jul 11, 2017 9:35 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Post Assessment #25
Replies: 1
Views: 410

Post Assessment #25

The meter was defined in 1963 as 1,650,763.73 wavelengths of radiation emitted by krypton-86. What is the wavelength of this krypton-86 radiation? To what region of the electromagnetic spectrum does this wavelength correspond? What energy does one photon of this radiation have? Can I get some help s...
Tue Jul 11, 2017 12:28 am
Forum: Photoelectric Effect
Topic: How to calculate the kinetic energy, energy and frequency? [ENDORSED]
Replies: 14
Views: 3338

Re: How to calculate the kinetic energy, energy and frequenc[ENDORSED]

The steps to solve the problem are: 1. Use Ek = 1/2 mv^2 2. 2. Divide the total energy (work function) by Avogadro's number. 3. Use: kinetic energy of e- = energy of incoming photon – work function ****In addition to covering this in class, the course reader has detailed examples as does the textbo...
Sun Jul 09, 2017 11:46 pm
Forum: DeBroglie Equation
Topic: Exercise 1.39 [ENDORSED]
Replies: 4
Views: 599

Exercise 1.39[ENDORSED]

A baseball must weigh between 5.00 and 5.25 ounces (1 ounce = 28.3g). What is the wavelength of a 5.15-ounce baseball thrown at 92mph?
Can someone walk me through the steps please? Thanks!
Sun Jul 09, 2017 10:38 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exercise 2.51
Replies: 1
Views: 333

Exercise 2.51

How many unpaired electrons are predicted for the ground-state configuration of each of the following atoms:
a)Bi
b)Si
c)Ta
d)Ni

How is the answer for part c 3 unpaired electrons?
Sun Jul 09, 2017 9:01 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Effective Nuclear Charge 2.37
Replies: 1
Views: 264

Effective Nuclear Charge 2.37

Can someone explain what the effective nuclear charge is? I don't really understand why part a of this question is false.
Sun Jul 09, 2017 8:15 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Question 2.17
Replies: 1
Views: 317

Question 2.17

Since the question is asking for the amount of orbitals in subshells with l equaling a certain number, does that mean we are looking for the magnetic quantum number?
Sun Jul 02, 2017 10:37 pm
Forum: Balancing Chemical Reactions
Topic: Fundamental H11
Replies: 2
Views: 514

Fundamental H11

I was hoping someone could explain what methods you used to balance the equation. I balanced iron first, but then got confused with how to balance the rest. How did you figure out that 4 moles of Co and Co2 were needed?
Sun Jul 02, 2017 6:54 pm
Forum: Molarity, Solutions, Dilutions
Topic: problem g13 help
Replies: 3
Views: 427

Re: problem g13 help

What do we do with the 3.0L of water?
Sat Jul 01, 2017 1:30 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Fundamentals E.35
Replies: 2
Views: 453

Fundamentals E.35

The decay of teeth can be slowed by the use of fluoridated toothpaste. The fluoride ions convert the hydroxyapatite in tooth enamel into fluorapatite. If all the hydroxyapatite is converted into fluorapatite, by what percentage does this conversion increase the mass of enamel? I found the molar mass...
Thu Jun 29, 2017 5:44 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Fundamental E3
Replies: 1
Views: 630

Fundamental E3

Question: In a nanotechnology lab you might have the capability ti manipulate individual atoms. The atoms on the left are gallium atoms (molar mass 70 g/mol), those on the right are atoms of astatine (molar mass 210 g/mol). How many astatine atoms would the pan on the right have to contain for the m...