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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: cindyy on February 23, 2010, 05:31:34 pm

Title: Cindyy's Question Thread!
Post by: cindyy on February 23, 2010, 05:31:34 pm
Since i have been posting quite a lot of questions up lately, i decided it was time to do this!
so here it is ...

My first question:

The initial 250mL of fertiliser solution was diluted 10 times by taking a 25mL sample from a diluted solution and diluting it to 250mL again.  What is the concentration of phosphate ions in ml/L, in the initial 250mL of fertliser?
The mass of the fertiliser is 0.0310g

-thanks
Title: Re: Cindyy's Question Thread!
Post by: Studyinghard on February 23, 2010, 07:18:59 pm
Is it me or theres not enough info to answer this question?
Title: Re: Cindyy's Question Thread!
Post by: appianway on February 23, 2010, 07:21:22 pm
That's what I was thinking... although I might be wrong, which is why I didn't post initially. What's reacting with what? And if it's a gravimetric, what's the mass of the precipitate? I presume the mass of the fertiliser is included to find the percentage purity...
Title: Re: Cindyy's Question Thread!
Post by: stonecold on February 23, 2010, 07:22:46 pm
isn't fertiliser (NH3)3PO4
?
Title: Re: Cindyy's Question Thread!
Post by: stonecold on February 23, 2010, 07:29:19 pm
is the answer 8.49 x 10^-4 M
?
Title: Re: Cindyy's Question Thread!
Post by: superflya on February 23, 2010, 07:30:52 pm
isn't fertiliser (NH3)3PO4
?

i dont think theres a generic type of fertiliser :s i could be wrong. u need more info.
Title: Re: Cindyy's Question Thread!
Post by: cindyy on February 23, 2010, 07:34:52 pm
no need to stresss! I totally just visited my tutor before, and i figured out how to do it .... and yes, it was missing a concentration! Lol sorry!
its coz this question was from a prac, and i didnt know what the concentration was (all good now) sorry guys!
Title: Re: Cindyy's Question Thread!
Post by: coletrain on February 23, 2010, 07:36:08 pm
heinemann chemistry strikes again!