Question

Question

Answer 1

Attached here

Answer 2

@Rushwr

Answer 3

223.

Vapor pressure and temperature are proportional b/c when you raise the temperature the fraction of molecules that can escape into the gaseous phases increases and therefore the vapor-presure goes rises.

Hydrogen bonding, this would affect vapor pressure because it is a property that depends on Intermolecular forces. the presence of hydrogen bonding between molecules would require more energy to break those bonds and allow those molecules to get into the gaseous phase. (i'm guessing that this would lower the vapor pressure).

The presence of solutes is a colliagitive property, one that depends on the number of molecules one dissolves into a solvent, rather than their identity. adding a solute would technically raise the boiling point because it would just take longer for those molecules to go from (l)-->(g). I think it would affect vapor pressure.

External pressure: the vapor pressure continues to rise until it equals the external pressure, and boiling occurs. although the external pressure will dictate when a substance will boil, it does not have a direct effect on the vapor pressure in my opinion.

I believe that the answer is External pressure

Answer 4

@Bozhena thoughts on 221?

Answer 5

I try to figure out which between A and D

Answer 6

222. is D, Cus Carbonates, Phosphates,sulfides are insoluble

Answer 7

224. This question relates to a gases solubility in water..

@rushwr thoughts? not sure..about gas suability in liquids?

\[HCl _{g} + H _{2}O(l) ---> H _{3}O ^{+} + Cl- \]

Answer 8

224.

To me why would HCL exist primarily as molecules? it would most likely be H+ + Cl-
to me A was false.

B I believe that this is that answer because you've have in situ all the gas dissolved and reacted already so you would also have Cl- ions in your solution.

C. from the formula I wrote above hydronium ion concentration would go up. Cl- does not raise the pH

i think it's B.

Answer 9

@Bozhena you were right

222. D
223. A
224. B

Answer 10

how do we figure out whether a gas is soluble in a solution? (it's like dissolves like right?)

Answer 11

The dissolving of a gas in water depends on the interaction between the molecules of the gas and the water molecules. As water is polar and HCl too they will interact with eachother

Answer 12

Ah I see, the last question we have is 221, I will post some more for us to discuss

Answer 13

221. D.

Answer 14

I'm sorry i couldn't join the convo sum problem with my internet connection @Photon336

Answer 15

Here's a great example of how the external pressure is EXTREMELY important to vapor pressure!
https://www.youtube.com/watch?v=pOYgdQp4euc

Answer 16

that's so cool. But i dont get why it freez

Answer 17

@Woodward that's a great video, how would you describe this?

Answer 18

It freezes because of this fine equation:

PV=nRT

We know the room was kept at a constant temperature, the volume of that glass thing covering it was a constant, but they lowered the pressure! What does that mean? They had to have removed particles, it's the only thing left free in the equation!

\[P=n*\frac{RT}{V}\]

So now what does removing particles do? Well now there's no longer anything for molecules in the water to hit up against, there's no more atmosphere! The water molecules are now free to escape, there's no longer a counteracting external pressure.

You gotta realize that water molecules are basically weightless on their own, so once they leave they leave into the air and the get sucked out with the pump allowing more to keep bouncing out.

But what's left? Just the slow moving water molecules. So really most of the heat left with the ones that bounced out. Keep in mind that they froze into a solid but they're still about 273 Kelvin above absolute zero, so they're still warm in some sense!