Question

Equal volumes of 1M $K_2{SO}_4$ and 1M ${Al}_2{\left({SO}_4\right)}_3$ solutions are mixed. Which of the following is incorrect?

• A. The concentration of $K^{+}$ is 1M
• B. The concentration of ${Al}^{3+}$ is 1M
• C. The concentration of ${SO}_4^{2-}$ is 2M
• D. The concentration of all the three ions is 1M

Answer 1

The correct option is D The concentration of all the three ions is 1M

Let the volumes be V. Total volume is 2V.
Moles of $K^{+}=2V$ Therefore molarity of $K^{+}=1M$
Moles of $A{l}^{3+}=2V$ Therefore molarity of $A{L}^{3+}=1M$
Moles of $S{O}_4^{2-}=4V$ Therefore molarity of $S{O}_4^{2-}=2M$