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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: /0 on August 02, 2008, 10:27:50 pm

Title: Concentration of solution
Post by: /0 on August 02, 2008, 10:27:50 pm: What mass of solute is needed to prepare 400 mL of 0.850 M $\mbox{CuSO}_4$ from $\mbox{CuSO}_4.\mbox{5H}_2\mbox{O}$ ? thx
Title: Re: Concentration of solution
Post by: Mao on August 02, 2008, 10:39:34 pm: hint: you want $0.4L\times 0.850M$ moles of $\mbox{CuSO}_4\cdot5\mbox{H}_2\mbox{O}$
Title: Re: Concentration of solution
Post by: /0 on August 02, 2008, 10:47:20 pm: thanks mao...
What's actually happening in the question though? Is the $\mbox{CuSO_4.5\mbox{H_2\mbox{O}}}$ splitting up to form a precipitate? Also is there another liquid or is it just $\mbox{CuSO_4.5\mbox{H_2\mbox{O}}}$ in liquid state?
Title: Re: Concentration of solution
Post by: Collin Li on August 02, 2008, 11:08:23 pm: The hydrated copper sulfate complex ion is a coordination compound.

A coordination compound involves a central cation (transition metal, as far as I know), which then links to a number of ligands. There are multiple arrangements, but common arrangements include the tetrahedral, square planar and octahedral arrangement.

$\mbox{CuSO_4.5\mbox{H_2\mbox{O}}}$ is in an octahedral arrangement. There are 6 ligands there: 5 aqua ligands and the sulfate ion ligand.

These coordination compounds (complex ions) were a mystery to chemists before they understood their structure. Read about them here.
Title: Re: Concentration of solution
Post by: Mao on August 02, 2008, 11:26:55 pm: what coblin tried to say was

treat the complex compound as a molecule in its own right and don't worry about it much more for the sake of VCE Chemistry :P
Title: Re: Concentration of solution
Post by: /0 on August 03, 2008, 01:22:37 am: Lol ok thanks guys