Calculate the sodium ion concentration when 72.5 mL of 4.4 M sodium carbonate is added to 32.6 mL of 2.5 M sodium bicarbonate.

moles Na2CO3 = M x L = ??

moles Na ion in that solution is twice Na2CO3.

moles NaHCO3 = M x L = ??
moles Na ion = same as NaHCO3.

(Na^+) = total moles Na^+/total L of solution.