Question 61

The percentage strength of the final volume will be 2.50%.

When 250 mL of a 10% solution of methyl salicylate in alcohol is diluted to a total volume of 1000 mL, the resulting concentration is 2.50%. This is calculated by determining the total amount of methyl salicylate in the original solution and then finding its concentration in the new total volume.

A) 0.25%

This option is incorrect because 0.25% would imply a far lower concentration than what is present after dilution. The original 10% solution, when diluted, does not decrease to such a minimal concentration.

B) 2.50%

This option is correct because when 250 mL of a 10% solution is diluted to 1000 mL, the total amount of methyl salicylate remains constant. The amount in grams from the original solution is 25 grams (10% of 250 mL), and when this is diluted to 1000 mL, the concentration becomes 2.5 grams per 100 mL or 2.50%.

C) 10%

This option is incorrect as it suggests that the concentration remains the same after dilution. Dilution inherently reduces the concentration, so the final concentration cannot be equal to the original 10%.

D) 25%

This option is incorrect because 25% would imply a concentration much higher than the original solution. The process of dilution reduces the percentage concentration, and therefore it cannot exceed the original percentage concentration.

Conclusion

The correct answer, 2.50%, accurately reflects the concentration after dilution from the original 10% solution. All other options are incorrect as they misrepresent the effects of dilution on concentration, either by suggesting a concentration that is too low or too high. Understanding the principles of dilution is essential for accurately calculating final concentrations in solutions.