Yo what volume should 5.0g of KCl be diluted in order to prepare a 0.25 M solution?

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Answer 1 · 2018-03-22T19:15:52

0.268L

#Given:#
Mass = 5.0g of KCl
Concentration = 0.25M KCl
Molar Mass KCl = 74.5513g/mol
Volume = ?

We can use the molarity formula to solve this, which is

#"Molarity"="moles of solute"/"litres of solution"#

However since we are trying to find the volume, we use the following formula (rearranged):

#"Volume"="moles of solute"/"molarity"#

Also, our value 5.0g KCl is not in moles quite yet so we convert that in terms of moles of KCl, using the mole formula,

#"Moles"="mass"/"molar mass"#

#n_(KCl)="5.0g"/"74.5513g/mol"#

#n_(KCl)=0.067067.....mol#

Next we plug in the given values into the volume formula.

#"Volume"="moles of solute"/"molarity"#

#V_(KCl)="0.067067.....mol"/"0.25L"#

#V_(KCl)=0.268...L#

#:.# #"5.0 g KCl"# should be diluted to #"0.268 L"# in order to prepare a #"0.25 M KCl"# solution.