Search found 17 matches

by halabaradi_1A
Fri Mar 17, 2017 1:06 pm
Forum: *Cycloalkanes
Topic: 2015 Practice Final 9A
Replies: 1
Views: 737

2015 Practice Final 9A

On this question, the second example, I am very confused as to the order in which they put the name? Why is it not 3-chloro-1-(2-methylpropan-2-ol) cycloheptane?
by halabaradi_1A
Fri Mar 17, 2017 12:54 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: How to draw the most stable cyclohexane conformations
Replies: 1
Views: 302

How to draw the most stable cyclohexane conformations

Hi, so I understand how to draw the conformations when given the names cis or trans, but if the question does not specify, and only asks for the most stable conformation, how would you determine that? Is it safe to assume that in most cases it will be trans and that the largest substituent is equato...
by halabaradi_1A
Fri Mar 03, 2017 5:43 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.67b Question
Replies: 1
Views: 337

15.67b Question

On part a of this question, it asked you to calculate the factor by which the rate of the reaction increased at 298K. This was found to be 6x10^8. But, of part b, it asked you to calculate the same thing but at 350K. The solution manual says that the rate decreased with the increase in temperature. ...
by halabaradi_1A
Sun Feb 26, 2017 2:31 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Question 34 in the Organic Chemistry Textbook
Replies: 1
Views: 326

Question 34 in the Organic Chemistry Textbook

I am having some trouble understanding which atoms donate electrons to form bonds for this reaction: CH3Br + OH- in equilibrium with CH3OH + BR-.
The problem says that it is a mechanism but I am having trouble with coming up with the first step!
by halabaradi_1A
Sat Feb 11, 2017 7:08 pm
Forum: Balancing Redox Reactions
Topic: Redox Reactions (Under Acidic/Basic Solutions) [ENDORSED]
Replies: 2
Views: 387

Re: Redox Reactions (Under Acidic/Basic Solutions) [ENDORSED]

The first step is to always separate the overall even reaction into an oxidation and reduction reaction. You can tell what substances are being oxidized and reduced by calculating their oxidation numbers beforehand in the given equation and seeing which species are losing and which are gaining elect...
by halabaradi_1A
Sun Feb 05, 2017 9:56 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode/Cathode
Replies: 4
Views: 544

Re: Anode/Cathode

The purpose of the salt bridge is to keep the reactions neutral so they can continue to pass electrons from anode to cathode. It keeps the anode from becoming too positive and the cathode from becoming too negative, otherwise the cell will stop working. The negative ions of the salt go to the anode ...
by halabaradi_1A
Sun Jan 29, 2017 5:08 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy at Equilibrium
Replies: 1
Views: 276

Re: Gibbs Free Energy at Equilibrium

Yes, I believe that when a system is at Equilibrium, delta G is zero. This is because at equilibrium, K would be equal to 1, causing the equation delta G=-RTlnK to equal zero because the ln1 is zero.
by halabaradi_1A
Fri Jan 20, 2017 6:38 pm
Forum: Phase Changes & Related Calculations
Topic: 8.29 in Textbook [ENDORSED]
Replies: 2
Views: 471

Re: 8.29 in Textbook [ENDORSED]

Molar heat capacity is the amount of energy it takes to raise the temperature of 1 mole of a substance by 1 degree Celsius. Since NO2 is a stable molecule, it needs more energy in order to raise its temperature. NO is a radical, and very unstable, so its bonds are not very strong. Thus, its heat cap...
by halabaradi_1A
Sat Jan 14, 2017 3:51 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: HW Problem 8.73 Bond Enthalpy
Replies: 2
Views: 444

HW Problem 8.73 Bond Enthalpy

The question is to use bond enthalpies to estimate the reaction enthalpy for this reaction: 3C2H2(g)--> C6H6(g). I know that C2H2 has a triple bond, so its bond enthalpy is 837 kJ/mol and benzene is 518. But I am wondering why the solution manual says that there are 6 moles of benzene if only 3 bond...
by halabaradi_1A
Sat Dec 03, 2016 8:49 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Finding the pH at the halfway point
Replies: 1
Views: 634

Finding the pH at the halfway point

How do you find the pH at the halfway point in a weak acid-strong base titration?

by halabaradi_1A
Tue Nov 22, 2016 8:35 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic and Endothermic
Replies: 4
Views: 1015

Re: Exothermic and Endothermic

If a reaction is exothermic, then it gives off heat, so the way I do it is at the products side of an equation, I just add "+heat" at the end. If the question asks what would happened of you decrease heat, then just apply Le-Chatleir's Principle, and the reaction proceeds to the right. If ...
by halabaradi_1A
Fri Nov 11, 2016 1:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Practice 3Quiz Prep 1
Replies: 1
Views: 413

Practice 3Quiz Prep 1

Can someone please explain how to do number 10 on the quiz three prep 1? It gives you the moles and Kp but asks for partial pressure. How do you convert moles to pressure?

by halabaradi_1A
Fri Oct 21, 2016 3:07 pm
Forum: Lewis Structures
Topic: Chapter 3, Number 23 Homework Problem
Replies: 1
Views: 295

Re: Chapter 3, Number 23 Homework Problem

An oxidation state is when an atom has the ability or tendency to lose are gain electrons to get a noble gas configuration. For the positive chlorine configuration, assume that chlorine is losing seven electrons to have a neon-like configuration. Thus, it's positive oxidation state is plus 7. For ne...
by halabaradi_1A
Fri Oct 14, 2016 8:24 pm
Forum: Ionic & Covalent Bonds
Topic: Excited state help
Replies: 1
Views: 307

Re: Excited state help

An electron can go into an excited state because it absorbs the specific required energy needed to jump to a higher orbital. At this state, the atom is unstable and not at the lowest energy. When the electron falls back to the ground state, it emits energy in the form of photons. When looking at the...
by halabaradi_1A
Wed Oct 05, 2016 10:05 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra #8 in Fall 2015 Quiz Prep [ENDORSED]
Replies: 1
Views: 371

Atomic Spectra #8 in Fall 2015 Quiz Prep [ENDORSED]

The question is: What is the wavelength of the radiation emitted when an electron transitions from n=4 to n=3? I know how to go about solving the problem by finding the change in energy between the levels using E=-hR/n^2, but I keep getting the wavelength as 1870 nm, when the answer says 1875nm. I h...
by halabaradi_1A
Mon Sep 26, 2016 7:28 pm
Forum: Properties of Light
Topic: Wavelength and Energy
Replies: 3
Views: 1254

Wavelength and Energy

Does anyone know how to solve problem numbers 23 and 25 on the chapter one homework? I've tried many times and I can't seem to figure them out!

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