Question

The absorbance of 10 ml of a 0.0005 M CO₂ solution is 0.35. 10 ml of this solution mixed with 10 ml of the sample solution produces an absorption of 0.52. Calculate the concentration of CO₂ in the sample.

a. 0.0009 M
b. 0.0012 M
c. 0.0015 M
d. 0.0020 M

Answer 1

To calculate the concentration of CO₂ in the sample, we can use the Beer-Lambert Law. By setting up the appropriate equation and plugging in the given values, we find that the concentration of CO₂ in the sample is approximately 0.000337 M.

Step-by-step explanation:

To calculate the concentration of CO₂ in the sample, we can use the Beer-Lambert Law. The absorbance of a solution is directly proportional to the concentration of the absorbing species.

Let's denote the concentration of CO₂ in the sample as x M.

According to the given information, the absorbance of 10 ml of the 0.0005 M CO₂ solution is 0.35. The absorbance of 10 ml of the mixture of 10 ml of the 0.0005 M CO₂ solution and 10 ml of the sample solution is 0.52.

Using the Beer-Lambert Law, we can set up the following equation:

A = εcl

Where A is the absorbance, ε is the molar absorptivity, c is the concentration, and l is the path length.

Since we have the same path length for both solutions, we can rewrite the equation as:

c₁ = (A₁/A₂) * c₂

Where c₁ is the concentration of the CO₂ solution and c₂ is the concentration of the sample solution.

Plugging in the values:

c₁ = (0.35/0.52) * 0.0005 M

c₁ ≈ 0.000337 M

Therefore, the concentration of CO₂ in the sample is approximately 0.000337 M.