Search found 29 matches

by Sarah Wax 1G
Sun Mar 18, 2018 11:45 pm
Forum: Balancing Redox Reactions
Topic: Adding OH
Replies: 6
Views: 302

Re: Adding OH

Remember to always balance OH with H2O, otherwise the equation won't balance in the long run.
by Sarah Wax 1G
Sun Mar 18, 2018 11:43 pm
Forum: General Rate Laws
Topic: Rate constant units
Replies: 6
Views: 426

Re: Rate constant units

Another thing I do is whatever the order is, the liters and moles will have an exponent one less than the order.

For fourth order, the rate constant = L^3/ mol^3 * S
For third order, the rate constant = L^2/ mol^2 * s
For second order, the rate constant = L / mol * s
by Sarah Wax 1G
Sat Mar 17, 2018 10:44 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: how much of catalyst do we need to know? [ENDORSED]
Replies: 4
Views: 286

Re: how much of catalyst do we need to know? [ENDORSED]

Basically, just know the properties of a catalyst, why they're used, how activation energy is affected, and calculations revolving around activation energies.
by Sarah Wax 1G
Sat Mar 17, 2018 10:43 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Iced tea and water problem
Replies: 2
Views: 301

Re: Iced tea and water problem

I also was conflicted on this question. I'm assuming since the ice cube starts as a solid when the reaction first goes, you need to use H of ice, and then once it's heated, use H of water.
by Sarah Wax 1G
Sat Mar 17, 2018 10:40 pm
Forum: *Ketones
Topic: Keytone and Aldeyhdes
Replies: 3
Views: 508

Re: Keytone and Aldeyhdes

I agree with the commentator above. Ketones have their oxygens somewhere within the chains while aldehydes only END their chains with O.
by Sarah Wax 1G
Mon Mar 05, 2018 12:01 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

What did one titration tell the other?
Let's meet at the endpoint.
by Sarah Wax 1G
Sun Mar 04, 2018 11:59 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

Stop making electrochem jokes.
They're too charged.
by Sarah Wax 1G
Sun Mar 04, 2018 11:58 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

How many fish are salty?

TuNA
by Sarah Wax 1G
Sun Mar 04, 2018 11:58 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

I believe that Uraniam Argon Copper Tellurium.

U Ar CuTe.
by Sarah Wax 1G
Sun Mar 04, 2018 11:56 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

There should be someone who regulates these chem jokes.

They're far too basic for my taste.
by Sarah Wax 1G
Sun Mar 04, 2018 11:56 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

Why did the sodium cross the road?

Because it could not wait N-A longer.
by Sarah Wax 1G
Sun Feb 18, 2018 11:58 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

Q: What do you do with a sick chemist?
A: If you can't helium, and you can't curium, then you might as well barium.
by Sarah Wax 1G
Sun Feb 18, 2018 11:58 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

Q: What do you call a clown who's in jail?
A: A silicon.
by Sarah Wax 1G
Sun Feb 18, 2018 11:57 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

Q: What did one ion say to the other?
A: I've got my ion you.
by Sarah Wax 1G
Sun Feb 11, 2018 10:42 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

It's so exciting when multiple electrons gather in the bar.
Why?
Because it's so charged with energy.
by Sarah Wax 1G
Sun Feb 11, 2018 10:41 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 7
Views: 204

Re: Salt Bridge

Like in lecture, a salt bridge keeps overall potential neutral, without which, electrons would build up at the cathode. A salt bridge must be used in order for the Galvanic cell to work.
by Sarah Wax 1G
Sun Feb 11, 2018 10:38 pm
Forum: Balancing Redox Reactions
Topic: Oxidation
Replies: 5
Views: 259

Re: Oxidation

I agree with the above responder. Basically, an oxidation number is the charge of an element within a certain compound. For example, in H2O, Hydrogen's oxidation number is +1 and Oxygen's is -2.
by Sarah Wax 1G
Sun Feb 04, 2018 10:58 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Quiz 1, #1
Replies: 2
Views: 158

Re: Quiz 1, #1

Exactly. There's a difference because one of the methods (bond enthalpies) relies on only the average bond energies/enthalpies for a certain bond. However the other method (enthalpies of formation) are specific to that molecule and tell you the exact energy which is needed to form it.
by Sarah Wax 1G
Sun Feb 04, 2018 10:56 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Test question [ENDORSED]
Replies: 16
Views: 564

Re: Test question [ENDORSED]

Yeah, I basically just put "energy can be neither created nor destroyed, only conserved." My TA told me that as long as you understood the concept, they didn't dock you for not being 100% accurate.
by Sarah Wax 1G
Sun Feb 04, 2018 10:54 pm
Forum: Van't Hoff Equation
Topic: Entropy and enthalpy
Replies: 2
Views: 192

Re: Entropy and enthalpy

I would agree with the above statement. If anything, assume that whatever details Lavelle leaves out of the question are going to be constant.
by Sarah Wax 1G
Sun Jan 28, 2018 3:15 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

Girl, do you like salt?

Why?

Because you're so-dium fine.
by Sarah Wax 1G
Sun Jan 28, 2018 3:12 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy calculated from Bonds vs Enthalpy of formation
Replies: 3
Views: 138

Re: Enthalpy calculated from Bonds vs Enthalpy of formation

Exactly. Using enthalpies of formation are a lot more accurate because it's the exact energy needed to form one mole of a substance. Bond enthalpies merely use averages of the exact energy needed to break/form a bond.
by Sarah Wax 1G
Sun Jan 28, 2018 3:07 pm
Forum: Phase Changes & Related Calculations
Topic: When to use Kelvin or Celsius
Replies: 10
Views: 464

Re: When to use Kelvin or Celsius

Everyone posting in this forum is correct. Usually, when using deltaT, it doesn't matter whether you use K or C because a change in temperature for either will result in the same numbers. However, when using just T in an equation, you need to use the other labels in order to determine whether or not...
by Sarah Wax 1G
Sun Jan 21, 2018 7:01 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: q(sys) = -q(surr)
Replies: 3
Views: 280

Re: q(sys) = -q(surr)

Usually, we just use -q(sys) = q(surr). That way everything remains simple. If we solve for the heat of system and we get q= -10 kJ, we know that the q of the surroundings is +10 kJ, and therefore the reaction of the system is exothermic. If the opposite signs occur, the reaction of the system is en...
by Sarah Wax 1G
Sat Jan 20, 2018 4:01 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Most Accurate Method [ENDORSED]
Replies: 3
Views: 116

Re: Most Accurate Method [ENDORSED]

Yeah, and remember that when using enthalpies of formation to check that the state of the molecule that you're using corresponds to the equation that you're trying to find the enthalpy for. Also: enthalpies of formation are the only enthalpies where you use (sum of products' enthalpies) - (sum of re...
by Sarah Wax 1G
Sat Jan 20, 2018 3:58 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 3 Test Topic is endorsed
Replies: 37
Views: 1805

Re: Week 3 Test Topic is endorsed

Also, anything involving bond enthalpies, enthalpies of formation, and calculating energy from a calorimeter will be on the test.
by Sarah Wax 1G
Sun Jan 14, 2018 6:39 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 890173

Re: Post All Chemistry Jokes Here

What did the chemist say to his crush?
You're hotter than a Bunsen burner turned up all the way.
by Sarah Wax 1G
Sun Jan 14, 2018 5:42 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law: Method 1
Replies: 3
Views: 181

Re: Hess's Law: Method 1

Adding up enthalpy changes using Method 1 is a smart way to go about finding the overall delta H. Essentially, if you don't have the net equation that you need in order to solve for H, then you can switch around and multiply equations in order to get your final solution. Like it's been said, equatio...
by Sarah Wax 1G
Sun Jan 14, 2018 1:19 pm
Forum: Calculating Work of Expansion
Topic: Homework Problem 8.9
Replies: 2
Views: 161

Homework Problem 8.9

Homework problem 8.9 asks us to calculate the internal energy of the gas using pressure (750 torr), an expansion in volume (+1501 mL), and a gain in energy (5.50 kJ). What equation do we use to calculate the internal energy of the gas given the fact that the system both gains energy in heat and does...

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