Question

A 10 ml co2 solution with 0.2m gives transmittance of 40% at 510nm while a 20ml co2 unknown has transmittance of 60% using the same cuvette in same solvent at the same wavelength. calculate the concentration of co2 in the unknown solution

Answer 1

The concentration of CO2 in the unknown solution is 0.5575 M. we can use the Beer-Lambert law, which states that absorbance is directly proportional to concentration. The equation is given as: A = εcl Where A is the absorbance, ε is the molar absorptivity, c is the concentration, and l is the path length.

Step-by-step explanation:

To calculate the concentration of CO2 in the unknown solution, we can use the Beer-Lambert law, which states that absorbance is directly proportional to concentration. The equation is given as: A = εcl Where A is the absorbance, ε is the molar absorptivity, c is the concentration, and l is the path length. Given that the transmittance of the 10 ml CO2 solution is 40% and the transmittance of the 20 ml CO2 unknown is 60% at the same wavelength, we can calculate the absorbance for both solutions: For the 10 ml solution: A = -log(0.4) = 0.3979 For the 20 ml solution: A = -log(0.6) = 0.2218.

Now, we can set up the following equation: A_1 = ε_1 * 0.2 * 1 A_2 = ε_2 * c * 1 0.3979 = 0.2 * ε_1 0.2218 = 0.2 * ε_2 * c Dividing the second equation by the first equation: 0.2218 / 0.3979 = ε_2 * c / ε_1 0.5575 = ε_2 * c / ε_1 Now, we can substitute the known values: 0.5575 = ε_unknown * c_unknown / ε_0.2 Since ε_0.2 and ε_unknown are both the same, we can simplify the equation to: 0.5575 = c_unknown Therefore, the concentration of CO2 in the unknown solution is 0.5575 M.