heh...

[Dudde]

you know, I have another basic question that I can't seem to get figured out *scratches head*

 

but I know how much you guys love science anyways:D

so...

 

calculate the pH of a solution formed by dissolving 0.045 moles of solid sodium lactate NaC3H5O3 in 250 mL of 05 M HC3H5O3. Assume that colume change is negligible

 

 

there are a few more like that too and I almost worked it out but that's alright:D I think if I get some sleep instead of trying to do it on an empty stomache and 2 hours of sleep I might be able to get it;) but I'm not that patient

[blike]

do they give the pHs of reactants??

[JaKiri]

I thought acidity and alkalinity only existed in water based solutions

[Dudde]

sorry, I worked out most of the other problems, not this one yet, I think the pH was..lemme check actually....the pH was 3.9 for the lactic acid (HC3H5O3)...

hm...

how annoying:rolleyes:

[Polverone]

This is only an approximation to the true pH, but it works well in many situations: pH = pKa + log([base]/[acid])

 

So in your case, divide the concentration of lactate by the concentration of lactic acid, take the log of that, and add it to the pKa of lactic acid to obtain the pH.

[Dudde]

oh yeah!! I just read that stupid formula and I forgot already:D

...maybe I should go through and read this stuff a bit more;)

hmm...

I guess this one, I don't know much about salts really, I have some basic guesses that might be right...:

 

AgCl BaCl2 CoCl2 NaCl NH4Cl

 

(A) what is the salt that can be distinguished by it's appearance alone? describe the observation that supports your identification.

 

(B) Identify the salt that can be distinguished by adding 10mL of water to a small sample of each of the remaining unidentified salts and describe your observation.

 

© Identify a chemical reagent that could be added to the salt identified in part (B) to confirm the salt's identity and describe your observation.

 

(D) Identify the salt that can be distinguished by adding Na2SO4 to a small sample of each of the remaining unidentified salts, describe the observation that supports your identification

 

(E) Identify the salt that can be distinguished by adding 1M NaOH to a small sample of each to the remaining unidentified salts and describe your observation

---

 

I haven't done much with salts, and I don't really have access to anything to help me test this out so it would have to all be theoretical, so I thought I'd get some help smarter than I am;)