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General Category => General Board => Homework Haven => Topic started by: BFM_MiG on September 07, 2008, 05:36:54 PM

Title: Chem 2 (college prep)**Dropped** yay!
Post by: BFM_MiG on September 07, 2008, 05:36:54 PM
im in Chem 2 (its a college prep course, and im not going to college to stuff anything with Chemistry lol)

well i need help in chemistry already (only a week and a half into the new school year)

here is my first one i dont remember/ understand:

1.) Calculate the mass of FeCl3 needed to prepare 250.0 mL of an aqueous FeCl3 solution that is 0.2500 Molarity in Cl- ion?
Title: Re: Chem 2 (college prep)
Post by: Rypto on September 07, 2008, 11:24:56 PM
Hey MiG,

I took Chemistry last year, so I might have forgotten some stuff, but let me try and help you.

1) Convert 250 ml to L; It will be 0.25 L
2) Molarity is mol of solute / L of solution, so write that out.
3) There are 3 Cl- required to make FeCl3, so 3 mol of Cl- is 1 mol of FeCl3
4) Use the period table to find the mass of FeCl3, and write that out.
5) Multiply and find your answer.



0.25 L FeCl3            0.25 mol Cl-              1 mol FeCl3                    162.35 g FeCl3
                      x    ---------------    x   ----------------     x    ---------------------   =  3.3823 g FeCl3
                             1 L FeCl3                    3 mol Cl-                        1 mol FeCl3
Title: Re: Chem 2 (college prep)
Post by: BFM_MiG on September 08, 2008, 12:04:46 PM
thanks Rypto, i checked and your right! ill be posting in this ALOT!  alot! i mean alot!
Title: Re: Chem 2 (college prep)
Post by: ·WídgêT· on September 09, 2008, 03:32:51 PM
I'm taking AP Chem this year, so I'll help out too  :yesyes:
Title: Re: Chem 2 (college prep)
Post by: BFM_MiG on September 14, 2008, 09:01:02 AM
i have to do a chem report today, so im sure i'll be posting alot of questions!!!



1000th post lol :drool:
Title: Re: Chem 2 (college prep)
Post by: BFM_Booyah on September 14, 2008, 09:22:04 AM
I'll get Mrs. Booyah to look at this thread.  She is a Chemist.....so yea....I think she can help.   :winkgrin:
Title: Re: Chem 2 (college prep)
Post by: BFM_MiG on October 02, 2008, 03:45:45 PM
im dropping the class. if i dont then i wont have special Senior privileges and i have enough science credits (plus it will bring my cumulative AVG down as well which is at 3.7 for my whole High School Career  :P)