Question

a 64.0 ml portion of a 1.70 m solution is diluted to a total volume of 268 ml. a 134 ml portion of that solution is diluted by adding 149 ml of water. what is the final concentration? assume the volumes are additive.

Answer 1

To find the final concentration, use the dilution equation M1V1 = M2V2. Calculate the concentration for each dilution step using the equation and the given volumes.

Step-by-step explanation:

To find the final concentration, we need to use the dilution equation. The equation is M1V1 = M2V2, where M1 and V1 are the initial concentration and volume, and M2 and V2 are the final concentration and volume. For the first dilution, the initial concentration is 1.70 M and the initial volume is 64.0 mL. The final volume is 268 mL, so we can solve for the final concentration. For the second dilution, the initial concentration is the previous final concentration and the initial volume is 134 mL. The final volume is 283 mL (134 mL + 149 mL of water), so we can solve for the final concentration again.

Let's use the dilution equation:

1. M1V1 = M2V2 (first dilution)
2. M2V2 = M3V3 (second dilution)

Plug in the values and solve:

1. (1.70 M)(64.0 mL) = M2(268 mL)
2. M2(268 mL) = M3(283 mL)

Solve for M2 and M3 to find the final concentrations.

Answer 2

To find the final concentration after two dilutions, use the dilution equation M1V1 = M2V2 for each step, where M1 and V1 are the initial molarity and volume, and M2 and V2 are the final molarity and volume after dilution.

Step-by-step explanation:

To calculate the final concentration of a solution after dilution, we can use the dilution equation M1V1 = M2V2, where M represents molarity and V represents volume. The initial portion of the solution has a volume of 64.0 mL and a concentration of 1.70 M. When this is diluted to a total volume of 268 mL, the concentration can be calculated using the equation (1.70 M)(64.0 mL) = M2(268 mL). Solving for M2 gives us the new concentration after the first dilution.

Then, a 134 mL portion of this newly diluted solution is further diluted by adding 149 mL of water. The concentration after this second dilution can be found by using the calculated M2 from the first step as M1 in the next step of the dilution equation: (M2)(134 mL) = M3(134 mL + 149 mL), where M3 is the final concentration after the second dilution. Solving for M3 gives us the final concentration of the solution.