What NaCl NaCl concentration results when 249 mL 249 mL of a 0.850 M 0.850 M NaCl NaCl solution is mixed with 667 mL 667 mL of a 0.420 M 0.420 M NaCl NaCl solution?

The answer to your question is 0.54M

Explanation:

Data

Final concentration = ?

Concentration 1 = 0.850 M

Volume 1 = 249 ml = 0.249 l

Concentration 2 = 0.420 M

Volume 2 = 0.667 M

Process

1. - Calculate the number of moles in both solutions

Number of moles 1 = Molarity 1 x Volume 1

= 0.850 x 0.249

= 0.212

Number of moles 2 = Molarity 2 x Volume 2

= 0.420 x 0.667

= 0.280

Total number of moles = 0.212 + 0.280

= 0.492

2.-Calculate the final volume

Final volume = Volume 1 + Volume 2

Final volume = 0.249 + 0.667

= 0.916 l

3. - Calculate Molarity

Molarity = 0.492 / 0.916

Molarity = 0.54