If 50.0 mL of a 0.10 M solution of sodium chloride is mixed with 50.0 mL of 0.10 M magnesium chloride, what is the molar concentration of chloride in the resulting solution?
I know the answer is 0.15 M but I don't know why. Can someone give me an explanation?
Thanks
I know the answer is 0.15 M but I don't know why. Can someone give me an explanation?
Thanks
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Sodium chloride dissolves in water.
NaCl ----> Cl- + Na+
The concentration of Cl- is the same as NaCl, at 0.10M
Magnesium chloride also dissolves
MgCl2 -------> 2Cl- + Mg2+
The concentration of Cl- is DOUBLE that of MgCl2, so it is 0.20M
The combined concentrations of the chloride ions is 0.30M, however you have doubled the volume (by adding two 50ml together), so the concentration is halved.
0.30M halved is 0.15M, as required :)
NaCl ----> Cl- + Na+
The concentration of Cl- is the same as NaCl, at 0.10M
Magnesium chloride also dissolves
MgCl2 -------> 2Cl- + Mg2+
The concentration of Cl- is DOUBLE that of MgCl2, so it is 0.20M
The combined concentrations of the chloride ions is 0.30M, however you have doubled the volume (by adding two 50ml together), so the concentration is halved.
0.30M halved is 0.15M, as required :)