Question

Indicate the concentration of each ion present in the solution formed by mixing the following. (Assume that the volumes are additive.)

15.0 mL of 0.346 M Na₂SO₄ and 13.0 mL of 0.200 M KCl

Na⁺ M

K⁺   M

SO₄^2-  M

Cl ^-   M

Answer 1

no of moles o f Na2SO4 = Molarity of Na2SO4 x volume of Na2SO4 in liters = 0.346M x 0.015 L = 0.0052 moles

no of moles of KCl = 0.2 M x 0.013L = 0.0026 moles

total volume = 0.015 + 0.013 = 0.028L

0.0052 moles will have 2 x 0.0052 Na+ ions = 0.0104 moles

Molarity of Na2So4 = 0.0104 / 0.028 = 0.3715 M Na+

no ofmoles of SO42- =0.0052

molarity of SO42- = 0.0052 / 0.028 = 0.1857 M SO42-

0.0026 moles of KCl will have 0.0026 moles of K+ and 0.0026 moles of Cl-

molarity of Cl^- = 0.0026 / 0.028 = 0.093 M Cl-

Molarity of K+ =  0.0026 / 0.028 = 0.093 M K+