five ml of colored solution has an absorbance of .500nm The absorbance of 10ml of the same solution is?
- A- 1.000nm
- B- 0.250nm
- C- 0.500nm
The correct answer is A. 1.000nm.
Here's why:
- Beer-Lambert Law:
This law states that the absorbance (A) of a solution is directly proportional to its concentration (c) and path length (l). It can be expressed as: A = ε * c * l, where ε is the molar absorptivity (a constant for a specific molecule at a specific wavelength).
- Same Solution:
Since it's the same colored solution, the molar absorptivity (ε) remains constant.
- Double the Volume:
Doubling the volume (from 5 ml to 10 ml) essentially halves the concentration (c).
- Constant Path Length:
Assuming the same cuvette is used for both measurements, the path length (l) remains constant.
Therefore, to maintain the same absorbance (A) with a halved concentration, the light needs to travel through twice the amount of solution. This doubles the product of c * l, resulting in an absorbance of 1.000 nm, which is double the original 0.500 nm.
Other Options:
Options B and C are incorrect because:
- 0.250nm (B):
This would be the absorbance if the concentration were halved and the path length remained the same. However, in this case, the path length doubles.
- 0.500nm (C):
This is the absorbance of the original 5 ml solution. Doubling the volume would double the absorbance.
