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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: NathanJ on March 27, 2014, 09:39:30 pm

Title: Finding mass of fertilizer.
Post by: NathanJ on March 27, 2014, 09:39:30 pm

Hey,

I'm really struggling with this question, I actually have no idea where to start.
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In the analysis of phosphorous you will prepare a 250ml solution of fertilizer. It is desirable for the concentration of phosphate ions (PO4 ^3-) to be about 50mg/L

If the fertilizer contains about 1.3% phosphorous by mass in the form of water soluble phosphate, calculate the approximate mass of fertilizer required to form the 250ml of solution. Show all workings.

I appreciate any help :)

Title: Re: Finding mass of fertilizer.
Post by: Phenomenol on March 27, 2014, 09:51:46 pm

Quote from: NathanJ on March 27, 2014, 09:39:30 pm

Hey,

I'm really struggling with this question, I actually have no idea where to start.
_______________________________________________________________________________________________________________________
In the analysis of phosphorous you will prepare a 250ml solution of fertilizer. It is desirable for the concentration of phosphate ions (PO4 ^3-) to be about 50mg/L

If the fertilizer contains about 1.3% phosphorous by mass in the form of water soluble phosphate, calculate the approximate mass of fertilizer required to form the 250ml of solution. Show all workings.

I appreciate any help :)

I'll give you a push in the right direction:

Find mass of phosphate ions required in the 250 mL solution.

Find mass of phosphorous in the form of phosphate ions required in the 250 mL solution.

The mass of fertilizer required can then be found.