You have three sodium carbonate solutions on a lab table in front of you. All of the solutions came from a 500.0-mL volumetric flask containing 3.00 M sodium carbonate. Solution 1 contains 100.0 mL of the 3.00 M solution.
Solution 2 contains 50.0 mL of the 3.00 M solution.
Solution 3 contains 10.0 mL of the 3.00 M solution.
What is the new concentration of Solution 2 if 13.2 g of solid sodium carbonate is added and dissolved? (Assume no volume change.)
A) 2.49 M
B) 11.5 M
C) 1.72 M
D) 5.49 M
E) 0.549 M

Question

Quizplus · Accepted Answer

The initial moles of sodium carbonate in Solution 2 is 0.15 moles (3.00 M * 0.050 L). Adding 13.2 g of sodium carbonate (0.125 moles) results in a total of 0.275 moles in 0.050 L, giving a concentration of 5.49 M.

You Have Three Sodium Carbonate Solutions on a Lab Table