Final answer:
To prepare 0.160 L of 0.550 M HNO₃ from a 5.20 M stock solution, you need 17 mL of the stock solution. When diluting 20.0 mL of this stock to a final volume of 0.330 L, the final concentration is 0.315 M.
Step-by-step explanation:
The calculation of the volume of a stock solution required to make a diluted solution, and the determination of the final concentration after dilution, can be accomplished using the dilution equation M1V1 = M2V2, where M1 and M2 are the molarities of the stock and diluted solutions, respectively, and V1 and V2 are the volumes.
A) To prepare 0.160 L of 0.550 M HNO₃ from a 5.20 M stock solution, you would use the following calculation:
(5.20 M)(V1) = (0.550 M)(0.160 L)
V1 = (0.550 M × 0.160 L) / 5.20 M
V1 = 0.017 L or 17 mL of the stock solution.
B) If you dilute 20.0 mL of the stock solution to a final volume of 0.330 L, the final concentration would be:
(5.20 M × 20.0 mL) / 330 mL
Concentration = 0.315 M after the dilution.