CHEMISTRY COMMUNITY

Michellekim1H

DHavo_1E wrote:Hello,

What would be an example of an intensive property? Thank you!

Intensive properties are properties that don't rely on the amount of substances but the type of matter. Examples would include temperature, color, and density.

Michellekim1H

I don't know what exactly calorimeters are and I don't know what the differences are either. Can someone please explain how we're also going to use them in problems as well?

Michellekim1H

I believe we have to review everything from outlines 1-4 including gibbs free energy but anything after that won't be covered in the test.

Michellekim1H

We never include solvents/liquids and solids for K and Q. Only aq and g are accepted.

Michellekim1H

Can anyone send me notes or tell me what was being taught on February 3? I had to miss class due to an appointment. Thanks in advance!

Michellekim1H

According to the textbook, it just means that there's o heat transfer between the system and its surroundings even if there's a temperature difference.

Michellekim1H

Could someone please explain the concept of this and give an example? Also, are we supposed to know/understand equation involving the integral(for the work of a reversible, isothermal expansion of an ideal gas) that Lavelle showed during class? Or was that just a demonstration of how we got to w = -...

Michellekim1H

A way to understand the difference between a closed and isolated system could be used by some examples. For a closed system, think of an ice pack. A closed system is defined as a system that exchanges energy with its surroundings but no matter comes out of it. An ice pack is closed but can still exc...

Michellekim1H

Basically, because hydroiodic acid is a strong acid, it dissociates completely in an aqueous solution. This means that the hydronium concentration is equivalent to the initial molarity of the acid. The back of the book represented this value in micromoles, so instead of just writing it as 6.0x10^-5...

Michellekim1H

Estimate the concentrations of (a) H3O+ and (b) OH- at 25 C in 6.0 × 10^-5M HI(aq).

The answer for a is 60.μmol⋅L^-1 and for b it's 0.17nmol⋅L^-1. Can someone tell me how to approach this problem?

Michellekim1H

I think for all questions concerning ICE tables, it’s okay to assume that x is an extremely small number if K(Ka, KB, etc) if is less than 10^-3. For this specific type of problem, if x is less than 5% of the initial acid then the approximation should be fine.

Michellekim1H

I’m still having a hard time comprehending what enthalpy is. Could someone please explain to me the concept is in simple terms and possibly even provide an analogy/example?

Michellekim1H

In lecture, Lavelle had on his slide the following:
Note: If [H3O+] < 10^-7 then the solution is neutral because we know autoprotolysis makes 10^-7 mol/L H3O+.

I don’t understand how this is possible, can someone please explain this to me? Wouldn’t the solution be more basic?

Michellekim1H

Positive delta H is endothermic(since there’s more energy in the products) whereas negative delta H is exothermic(there’s less energy in the products).

Michellekim1H

Can someone explain to me the concept of state property? During lecture, I've written down in my notes that state properties can be added or subtracted which I don't understand. Additionally, I've written down that work and heart depend on a path taken and they're not state properties. Can someone p...

Michellekim1H

The principle states that reactions adjust to reduce the effects of a changing system. It will basically try to go into equilibrium state. For instance, think about how we can create more products without adding more reactants. We are able to get more products by actually removing them in which the ...

Michellekim1H

Solids and liquids aren't included in the equation because the equation takes into account concentration. It's common sense that solids don't have concentration whereas for liquids, since most are solvents in large excess, it would not really affect the reaction. Therefore, we can just remove solids...

Michellekim1H

First, if given grams, then convert it to moles. Afterwards, input what you have as moles in the ideal gas law equation but rearrange it to get P alone.

Michellekim1H

It basically means that a proton is transferred between the same molecule. For example, 2H2O(l) <-> H30+(aq) + OH-(aq).

Michellekim1H

The test will cover everything we learned from outlines 1 and 2 (from chemical equilibrium to acids and bases). Anything we learn after that(from week 3) won't appear on the test.

Michellekim1H

What happens when Q>K, Q<K, and Q=K, and why? When Q>K: The reaction is favoring the reverse reaction because there’s more products formed. When Q<K: The reaction is favoring the forward reaction because more reactants are made. As a result, it wants to create more products with the excess reactant...

Michellekim1H

Consider the following reaction at 1200 K, for which you know Kc = 1.7 x 10-3. Br2 (g) ⇌ 2 Br (g) Your experimental setup is able to measure the equilibrium concentration of Br2 based on its color, but you are unable to measure the concentration of Br directly. If you measure at equilibrium [Br2] t...

Michellekim1H

Because K= Products/Reactants, when K > 10^3, this means that products are being favored since K would be large(thus, shifting to the right). When K<10^-3, the reaction favors reactants because K would be small(shifting to the left).

Michellekim1H

Kp is only used for partial pressure(for gases) whereas Kc is just the equilibrium constant regarding molar concentrations.

Michellekim1H

So, I know that solids and liquids are not supposed to be included in Kc but I was wondering if Aq is excluded as well. Isn’t Aq liquid too? Also, I still don’t really understand why these things are excluded from the expression so can someone please explain to me why.

CHEMISTRY COMMUNITY

Search found 25 matches

Re: extensive property

Calorimeter and Bomb Calorimeter

Re: Topics on the Midterm

Re: solids and liquids in the rxn quotient

Lecture on Feb.3

Re: adiabatic systems

Reversible Expansion

Re: Closed vs isolated systems

Re: Self-Test 6A.3A

Self-Test 6A.3A

Re: Assuming X

Enthalpy

H3O+ < 10^-7 Neutral?

Re: Delta H

State Property

Re: Le Chatelier's Principle

Re: Solids and liquids

Re: Kp given instead of Kc

Re: Autoprotolysis

Re: Topics on Test 1

Re: Reaction quotient (Q)

Re: Chemical Equilibrium Part 2 Post Module #12

Re: Small K value and Large K value

Re: K vs Kp vs Kc

Are Both L and Aq Excluded From Equilibrium Constant Expressions?