A chromate πΆππ4 β2 solution has an absorbance of 1.534 when the cell length is 1.5 cm. If the molar absorptivity of chromate ion is 5.21 Γ 103 πβ1 ππβ1, calculate the concentration of chromate ion.
To calculate the concentration of chromate ion in the solution, we can use the Beer-Lambert Law. The Beer-Lambert Law relates the absorbance of a solution to the concentration of the absorbing species and the path length of the sample cell.
The Beer-Lambert Law is given by the equation:
A = Ξ΅ * c * l
where:
A is the absorbance of the solution,
Ξ΅ is the molar absorptivity (also known as the molar absorption coefficient) of the absorbing species,
c is the concentration of the absorbing species,
and l is the path length of the sample cell.
In this case, we are given that the absorbance (A) is 1.534, the molar absorptivity (Ξ΅) of chromate ion is 5.21 Γ 10^3 M^-1 cm^-1, and the path length (l) is 1.5 cm.
Plugging these values into the equation, we can solve for the concentration (c):
1.534 = (5.21 Γ 10^3 M^-1 cm^-1) * c * (1.5 cm)
To isolate c, we divide both sides of the equation by [(5.21 Γ 10^3 M^-1 cm^-1) * (1.5 cm)]:
c = 1.534 / (5.21 Γ 10^3 M^-1 cm^-1 * 1.5 cm)
c β 0.196 M
Therefore, the concentration of chromate ion in the solution is approximately 0.196 M.