Answer:
6.83x10⁻⁴M is the initial concentration of the Cu²⁺
Explanation:
The concentration is directly proportional to the signal (Beer-Lambert law).
The increase in concentration produce an increase in signal of:
45.1 units - 25.2 units = 19.9 units.
The increase in concentration is of:
0.500mL = 5x10⁻⁴L * (0.0275mol / L) = 1.375x10⁻⁵moles / 0.0255L = 5.39x10⁻⁴M
The conversion factor is 5.39x10⁻⁴M = 19.9 units
That means the initial concentration that produce a signal of 25.2 units is:
25.2 units * (5.39x10⁻⁴M / 19.9 units) =
6.83x10⁻⁴M is the initial concentration of the Cu²⁺
