Calling all younger reefers - Page 8

Billy1234 · #**176** 12/11/2005, 12:33 AM

I don't know what else to call it, and, as a matter of fact, I do know what a 'retort' is.

LeftCoast · #**177** 12/11/2005, 05:23 AM

Lighten up people. Either stop making jokes or learn how to take them better.

tsquad · #**178** 12/11/2005, 10:09 AM

Meh, Mike and Billy know each other personally, so I don't give it too much thought.

Kamko · #**179** 12/11/2005, 11:53 AM

Tyler you didn't reply to my cynical message and now I'm feeling ignored. That's it I'm through with you so don't call me again.

J/K

peacetypes6 · #**180** 12/11/2005, 03:19 PM

Quote:

Originally posted by FalsePerc
You lack a signature, and I'll bet you don't have a clue as to what a 'retort' is.

yeah well my dad can beat up your dad, haha back to 5th grade

Billy1234 · #**181** 12/11/2005, 05:48 PM

Quote:

yeah well my dad can beat up your dad, haha back to 5th grade

LeftCoast · #**182** 12/11/2005, 06:02 PM

I'm glad we're so mature.

tsquad · #**183** 12/11/2005, 06:07 PM

Quote:

Originally posted by Kamko
Tyler you didn't reply to my cynical message and now I'm feeling ignored. That's it I'm through with you so don't call me again.

J/K

Which message? I honestly have no idea what you're talking about.

Kamko · #**184** 12/11/2005, 07:18 PM

Quote:

Originally posted by Spiffman257
I'm glad we're so mature.

We wouldn't be having so much fun otherwise.

Billy1234 · #**185** 12/11/2005, 08:23 PM

Quote:

Originally posted by Kamko
We wouldn't be having so much fun otherwise.

I agree

FalsePerc · #**186** 12/11/2005, 08:26 PM

Quote:

Originally posted by Spiffman257
Lighten up people. Either stop making jokes or learn how to take them better.

Sarcasm = good.

LeftCoast · #**187** 12/11/2005, 08:31 PM

Quote:

Originally posted by FalsePerc
Sarcasm = good.

Sarcasm = bound to happen

tsquad · #**188** 12/11/2005, 09:32 PM

Kamil, I have a chem question...

Why do the alkali earth metal sulfates [MgSO4, CaSO4, BaSO4, to be precise] solubilities decrease as you go down the group?

tsquad · #**189** 12/11/2005, 09:56 PM

This is what I've come up with...

In this portion, we put 1.00g of each solid, MgSO4, CaSO4, and BaSO4 in test tubes. We then added 5mL of water to each test tube. The solutions were mixed, and the following resulted. The magnesium tube had 0.0 cm of undissolved solid left, leading us to believe MgSO4 is most soluble. The calcium tube has 1.0 cm of undissolved solid left, leading us to believe that CaSO4 is somewhat soluble. The BaSO4 tube has 1.5cm of undissolved solid left. This was all of the BaSO4 that was used. Looking at the solubility rules, SO4 compounds are insoluble when combined with Ba+2; therefore, the BaSO4 is insoluble.

The task was to find out why solubility decreases as you go down the group. As you go down the group, lattice enthalpy decreases along with hydration enthalpy. It gets easier to break the ions free from the crystal lattice and also to hydrate them as you go down the group. If the crystal lattice is weak, the compound is more soluble. MgSO4 has higher crystal lattice energy than CaSO4. This due to an ionic radius increase. As the ionic radius increases, the effective nuclear charge decreases, causing less attraction, and the crystal lattice energy decrease. When crystal lattice energy decreases, the hydration enthalpy decreases because the ions are not as attracted to the water molecules. Moving down the group, the hydration enthalpy and the crystal lattice energy decrease. This is because the atomic radii increase. The SO4-2 ion is much larger than that of the earth metal cation. Therefore, the hydration enthalpy decreases at a much faster rate than the lattice energy. So, as you move down the group, Drxn gives off more energy, and is more endothermic, and as the reaction becomes more endothermic, the less soluble a compound is. Hence, as you move down Group II, the less soluble the metal sulfate becomes. This is shown in the results, as MgSO4 was most soluble, followed by CaSO4, and BaSO4.

Kamko · #**190** 12/11/2005, 10:09 PM

Quote:

Originally posted by tsquad
This is what I've come up with...

In this portion, we put 1.00g of each solid, MgSO4, CaSO4, and BaSO4 in test tubes. We then added 5mL of water to each test tube. The solutions were mixed, and the following resulted. The magnesium tube had 0.0 cm of undissolved solid left, leading us to believe MgSO4 is most soluble. The calcium tube has 1.0 cm of undissolved solid left, leading us to believe that CaSO4 is somewhat soluble. The BaSO4 tube has 1.5cm of undissolved solid left. This was all of the BaSO4 that was used. Looking at the solubility rules, SO4 compounds are insoluble when combined with Ba+2; therefore, the BaSO4 is insoluble.

The task was to find out why solubility decreases as you go down the group. As you go down the group, lattice enthalpy decreases along with hydration enthalpy. It gets easier to break the ions free from the crystal lattice and also to hydrate them as you go down the group. If the crystal lattice is weak, the compound is more soluble. MgSO4 has higher crystal lattice energy than CaSO4. This due to an ionic radius increase. As the ionic radius increases, the effective nuclear charge decreases, causing less attraction, and the crystal lattice energy decrease. When crystal lattice energy decreases, the hydration enthalpy decreases because the ions are not as attracted to the water molecules. Moving down the group, the hydration enthalpy and the crystal lattice energy decrease. This is because the atomic radii increase. The SO4-2 ion is much larger than that of the earth metal cation. Therefore, the hydration enthalpy decreases at a much faster rate than the lattice energy. So, as you move down the group, Drxn gives off more energy, and is more endothermic, and as the reaction becomes more endothermic, the less soluble a compound is. Hence, as you move down Group II, the less soluble the metal sulfate becomes. This is shown in the results, as MgSO4 was most soluble, followed by CaSO4, and BaSO4.

Impressive, but I think you just need this part As the ionic radius increases, the effective nuclear charge decreases, causing less attraction, and the crystal lattice energy decrease. When crystal lattice energy decreases, the hydration enthalpy decreases because the ions are not as attracted to the water molecules. Putting it into less words the solubility decreases b/c the subsequent compounds get less "polar" (I used the quotes b/c they're ionic). Similar logic can be used for many other types of compounds except for oxyacids (I suggest you check it). Besides that, like I said: impressive.

LeftCoast · #**191** 12/11/2005, 10:40 PM

Very.

tsquad · #**192** 12/11/2005, 11:27 PM

Thanks Kamil. I'm finally finished with the whole thing, 5 pages. Want me to paste?

Kamko · #**193** 12/12/2005, 05:47 AM

Quote:

Originally posted by tsquad
Thanks Kamil. I'm finally finished with the whole thing, 5 pages. Want me to paste?

Sure why not... It should make for an interesting read after two finals which start at 7:30...

tsquad · #**194** 12/12/2005, 11:03 AM

I will paste when I get home, I just handed it in.

tsquad · #**195** 12/12/2005, 03:42 PM

It's the attachment

Kamko · #**196** 12/12/2005, 08:41 PM

Save for a few grammar errors, which are irrelevant, the lab was well written. To be honest, I feel lucky that we didn't have to go "overboard" in my ap chem class, like you guys.

Edit: I skimmed through parts of it so when I reread it more thoroughly I'll let you know.

tsquad · #**197** 12/12/2005, 10:26 PM

My teacher's nuts. We started this chapter last Monday, and did the lab in school on Tuesday/Thursday. She expected the entire chapter to be outlined (30pgs) by Friday, along with the lab being due Friday, and the Chapter test on Friday. However, we had a snowday on Friday, so everything was due today.

Now, we have to finish chapters 8 and 9 before December 23rd. Kill me please.

Kamko · #**198** 12/13/2005, 08:20 AM

Wow, we didn't have to outline anything...

tsquad · #**199** 12/13/2005, 02:56 PM

She doesn't check it. She does however check the problems at the back of the chapter. There's about 100 of them, we only do the odds. She checks, and then gives us a solution packet for the entire thing. Then, she expects us to finish the problems. She doesn't check those; however, on the tests, she always puts one or two of the evens on it, so that way she will know if we did the homework. She's EVIL

Kamko · #**200** 12/13/2005, 08:40 PM

Yeah well we didn't have any homework assignments, but that's probably why we had only four 5s in a class of 30 people (myself included). But then all those 5s were also on the chem-a-thon team (yup we kicked some major butt here at UF), so yeah. In completely unrelated news, I was finally able to finish Prince of Persia: The Sands of Time - really cool ending. Oh yeah, have any of you played F.E.A.R. or are you all console jockeys? Well, anyway I was reading some review online and this guy stated that sometimes you play along a swat team called SFOD-D. Swat team?! That would be Special Forces Operational Detachment - Delta and not some lame swat team... Sorry for going off the tangent again. So I have one more final this Thursday and three weeks off - can't wait...