Question

A 68ml portion of a 1.70 m solution is diluted to a total volume of 208ml. A 104 ml portion of that solution is diluted by adding 109ml of water. What is the final concentration?

Answer 1

The final concentration can be found using the dilution equation, applied twice for the two-step dilution process.

Step-by-step explanation:

To calculate the final concentration of the solution after dilution, we can use the dilution equation M1V1 = M2V2, where M1 and V1 are the molarity and volume of the initial solution, and M2 and V2 are the molarity and volume of the final solution, respectively. In your case, the initial molarity is 1.70 M, and the volume is 68 mL. After dilution to a total volume of 208 mL, we can calculate the new concentration, M2, using the dilution equation. Then, we take 104 mL of this solution and add 109 mL of water; thus, the total volume becomes 213 mL, and we can use the dilution equation again to find the final concentration.

First dilution step: (1.70 M) (68 mL) = M2 (208 mL)
Calculating M2 gives us the concentration after the first dilution. Next, we take this concentration (M2) and apply it to the second dilution step: (M2) (104 mL) = M3 (213 mL). Solving for M3 gives us the final concentration.