What NaCl concentration results when 304 mL of a 0.610 M NaCl solution is mixed with 562 mL of a 0.340 M NaCl solution?

Answer 1

The final concentration of NaCl will be the total moles of NaCl divided by the total volume in liters.

moles NaCl:

304 mls x 1 L / 1000 ml x 0.610 mol/L = 0.1854 mols NaCl

562 mlx x 1 L / 1000 ml x 0.340 mol/L = 0.1911 mols NaCl

Total moles = 0.1854 + 0.1911 = 0.3765 moles NaCl

Total volume (L) = 0.304 L + 0.562 L = 0.866 L

Final [NaCl] = 0.3765 mols / 0.866 L = 0.435 M (3 sig. figs.)