Chemistry 2006/ 2007 Club***

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Specializes in Telemetry Med/Surg.

Try this: http://ehs.vail.k12.az.us/~frankm/Chemistry.html

I use it all the time especially with the mole and Stoichiometry

JeanettePNP, MSN, RN, NP

1 Article; 1,863 Posts

Specializes in Pediatric Pulmonology and Allergy.

Can anyone explain how soap works? The specific wording of the question is:

In pioneer days, soap was made by boiling animal fat with lye (potassium hydroxide). The bonds linking the fatty acids to the glycerol molecule were hydrolized, and the potassium hydroxide reacted with the fatty acid to produce soap. A typical soap available today is sodium stearate. In water, it ionizes to produce sodium ions and stearate ions. Explain how soap functions to trap and remove particles of dirt and grease.

andrea5

13 Posts

thanks very much br107. I understand now yeah!:thankya:

droopy1592

190 Posts

Can anyone explain how soap works? The specific wording of the question is:

In pioneer days, soap was made by boiling animal fat with lye (potassium hydroxide). The bonds linking the fatty acids to the glycerol molecule were hydrolized, and the potassium hydroxide reacted with the fatty acid to produce soap. A typical soap available today is sodium stearate. In water, it ionizes to produce sodium ions and stearate ions. Explain how soap functions to trap and remove particles of dirt and grease.

http://chemistry.about.com/library/weekly/aa081301a.htm

key quote:

"

Soap is an excellent cleanser because of its ability to act as an emulsifying agent. An emulsifier is capable of dispersing one liquid into another immiscible liquid. This means that while oil (which attracts dirt) doesn't naturally mix with water, soap can suspend oil/dirt in such a way that it can be removed. "

emulsifying (bare with me, my own explanation) is when you have a bubble (sudsing) layer between an polar inorganic (water) later and an nonpolar organic (oil/dirt) layer. Water and oil don't mix because one is polar and one isn't. An emulsifier makes the oil wash away with the water my allowing them to mix because of the long molecule chain (in the soap). The long nonpolar part of the chain mixes with the oil and the polar part mixes with the water. The soap breaks up the molecules of oil and they mix freely with the water.

I think

JeanettePNP, MSN, RN, NP

1 Article; 1,863 Posts

Specializes in Pediatric Pulmonology and Allergy.

Thanks. That helped!

2bnurseforce1

412 Posts

Hello all I am late joining but I am in Intro to Chemistry and I am having a problem with balancing formulas any help.

droopy1592

190 Posts

Post a reaction your having problems with and I'll go over it + balance it.

klleo27

47 Posts

Hello all. I havent started any classes yet but I need to take Mirco, A&P I&II, and Chem. I want to start one class in the summer but I am not sure which one to start off first (and it is going to be a summer course!) Any suggestions? It would be online at ccconline. So I would have to do labs at home. Thanks!

laurawho7

82 Posts

Anyone have any tips or tricks for memorizing formulas? Our Professor wants us to memorize poloyatomic ions and be able to write out formulas for our up coming tests. I am struggling with trying to memorize it all and could use some pointers from those of you who do well in chemistry. I have made a "practice quiz" but I am still hung up on memorizing the compounds!

Thanks for all the help!:uhoh3:

droopy1592

190 Posts

this is for butterfly and fnhopeful- i can't pm fnhopeful because your storage is too full... so i'll post the balancing stuff here.

alright alright...

look, the whole thing you gotta do in balancing equations is to make sure you have the exact same amount of each atom on each side of the arrow.

n2 + h2 → nh3

here, nitrogen gas and hygrogen gas are your reactants, and ammonia is your product... but look, you have 2 nitrogen atoms on the reactant side and only one on the product side.... so let's multiply nh3 by two so we can have equal amounts of nitrogen on both sides.

n2 + h2 → 2nh3

so what's wrong here? we have two nitrogen on both sides! now we're getting somewhere. so we have two nitrogen on both sides, and now two hydrogren on the reactant side but six hydrogen (multiply your stichiometry, or mole value 2 times your amount of hydrogen in the molecule, which is three) on the product side. something's wrong here. so in order to get six hydrogen on the reactant side, we need to multiply h2 by three.

so now we have

n2 + 3h2 → 2nh3

so let's try again, you have two nitrogen on each side (n2 = 2n see, the 2 in n2 means that you have two nitrogen atoms in that molecule, but the 2 in 2n is you stichiometry value... or mole value). so we have equal nitrogen on both sides. count up the hydgrogen. 3 x 2 = 6 and 2 x 3 = 6 so we have six hydrogen on each side. this equation is now balanced. balancing equations is trial and error, it's not something you just look at and know where to start. you find an atom that has unequal numbers and you find a way to make it equal and you keep going until you figure it out. some can be tricky and you may even have to use fractions.

try this

hcl + sb2o3 -------> sbcl3 + h20

now we've got 1 chlorine on the reactant side and 3 on the product side. this is just an abitrarily selected starting point. you can start anywhere.

multiply hcl by 3 to get the same amount of chlorine on each side.

3hcl + sb2o3 -------> sbcl3 + h20

now i've got the right amount of cl, but the wrong amount of hydrogen on the other side (6 h on left, 2h on right)... hmm, how do i make 3h and h2 equal? i know, i'll find the least common denominator and make them equal. the lcd is 6, so i'm gonna find a way to get a total of six hydrogen on each side.

6hcl + sb2o3 -------> sbcl3 + 3h20

you're probably like "what the hell just happened?" well, this is a tricky one, so you've gotta get creative. i know we had equal chlorine on each side before, but we needed equal hydrogen also. that was the only way would could have fixed it and if we needed to go back to the sbcl3 and change it's value to make it balanced again then that's what we have to do. we need 6 chlorine on each side since we have 6hcl... so we multiply the sbcl3 on the product side by 2.

6hcl + sb2o3 -------> 2sbcl3 + 3h20

so now i've got 6h and 3 x h2 = 6 (on the product side), and 6cl on each side also so now i've got equal hydrogen and chlorine on each side. let's look at the oxygen. i have 3 oxygen on the reactant side and 3 on the product side... so oxygen is fine too. look at the antimony (sb, lol, weird name there) so because we balanced chlorine earlier sb is now also balanced. we got 2 on the reactant and 2 on the product side.

so let's count everything up

6 h on each side since 6h= 3xh2

6cl on each side since 6cl= 2xcl3

2sb on each side since sb2=2x1sb

3o on each side since o3=3x1o

so that equation is balanced....

6hcl + 1sb2o3 -------> 2sbcl3 + 3h20

remember, it's not done until you have equal amounts of each atom on each side.

droopy1592

190 Posts

anyone have any tips or tricks for memorizing formulas? our professor wants us to memorize poloyatomic ions and be able to write out formulas for our up coming tests. i am struggling with trying to memorize it all and could use some pointers from those of you who do well in chemistry. i have made a "practice quiz" but i am still hung up on memorizing the compounds!

thanks for all the help!:uhoh3:

there is no real trick, other than memorizing the one with the most oxygens (the -ate, except for iodate, bromate, and chlorate, then it's per-x-ate), how many oxygens it has and it's charge for each group. example, sulfur polyatomic anion sulfate is so4 with a negative charge of 2... so you know that sulfite has to be so3 with the same charge (-2). all of the -ates/-ites for each group (example: nitrate, nitrite have -1 and dihydgrogen phosphate/phosphite have -1) have the same charge, just different number of oxygens. -ates have 1 more oxygen than-ites so you have to atleast remember one for each group.

for chlorate, bromate and iodate- remember that it descends in this order

perchlorate clo4

chlorate clo3

chlorite clo2

hypochlorite clo

just change the name for the other two.

perbromate bro4

bromate bro3

bromite bro2

hypobromite bro1

easy! do iodate yourself. remember hypo means under, -ate is higher than -ite, and per is the highest. each lower one has one less oxygen... per- usually means there are four oxygen atoms.

all twelve of them have a single negative charge.

also remember that carbon and nitrogen are in period 2 and can't bond to as many oxygen as sulfur and phosphorus. one of those oxygen will always want a double bond (truly a hybrid when you consider resonance-- which will take forever to expalin) which is why they don't really bond to four unless the oxygen is bonded to a halogen or hydgrogen already in addtion to carbon. maybe that can help you to remember that co3 is carbonate and no3 is nitrate (c and n in period 2) and phosphorous (phosphate is po4 and sulfate is so4) and sulfur are in period 3 so they can bond to more oxygen atoms since they have more freedom in the valence shell.

i hope i'm making it too hard as some of this may be beyond what you've been taught in chem 1 and you will learn in organic chem.

droopy1592

190 Posts

Hello all. I havent started any classes yet but I need to take Mirco, A&P I&II, and Chem. I want to start one class in the summer but I am not sure which one to start off first (and it is going to be a summer course!) Any suggestions? It would be online at ccconline. So I would have to do labs at home. Thanks!

Er, you can't do chem labs at home. At least I don't think you can. Usually the online universities have local complexes where you go to do lab but you do the lecture online. If anything, do Chem and A and P together, or just chem first... that way when you do micro you won't be lost.

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