Question

250mLof a solution is prepared by mixing 0.05 moles of Na2CO3 and 0.1g of Na2CO3. find the molarity of the soliution?

Answer 1

$$\begin{gathered} Molarity=\frac{Noofmolesofsolute}{VolumeofthesolutioninL} \\ Noofmolesofsolute=0.05molesofN{a}_{2}C{O}_3+molesofN{a}_{2}C{O}_{3}from0.1g \\ =0.05+\frac{0.1}{106} \\ =0.05+9.43\times {10}^{-4} \\ =500\times {10}^{-4}+9.43\times {10}^{-4} \\ =509.43\times {10}^{-4} \\ Molarity=\frac{509.43\times {10}^{-4}}{0.250}=2037.72\times {10}^{-4} \\ =0.2038M \end{gathered}$$