Question

What NaCl concentration results when 204 mLof a 0.760 M NaCI solution is mixed with 417 mL of a 0.430 M NaCl solution?

Answer 1

`[NaCl]` `~=` `0.5*mol*L^-1`

Explanation:

`"Solution 1"`, `"moles of NaCl"` `=` `204xx10^-3*Lxx0.760*mol*L^-1=0.155*mol`.

`"Solution 2"`, `"moles of NaCl"` `=` `417xx10^-3*Lxx0.430*mol*L^-1=0.179*mol`.

Since we must consider the volumes to be additive when these solutions are mixed, we have the following concentration with respect to `NaCl`.

`"Concentration"` `=` `((0.155+0.179)*mol)/((204+417)xx10^-3*L)`

`~=` `0.5*mol*L^-1` with respect to `NaCl`.