The Henry's law constant for CO2 is 3.1 x 10-2 mol/L-atm at 25°C. What pressure would
be necessary in order to have a .25 M solution?
C = k*P
0.25 = k*P. Solve for P
0.000839
25/(3.1x10^-2)= 8.06
To find the pressure necessary to have a 0.25 M solution of CO2, we can use Henry's Law. Henry's Law states that the concentration of a gas in a liquid is proportional to the pressure of the gas above the liquid.
The equation for Henry's Law is: C = k * P
Where:
- C is the concentration of the gas in the liquid (in this case, CO2), measured in molarity (M)
- k is the Henry's Law constant for the gas in the specific solvent (in this case, CO2 in water)
- P is the partial pressure of the gas above the liquid, measured in atmospheres (atm)
Given:
- Henry's Law constant for CO2, k = 3.1 x 10^(-2) mol/L-atm
- Desired concentration of CO2 in solution, C = 0.25 M
We can rearrange the equation to solve for the pressure, P.
P = C / k
Substituting the given values:
P = 0.25 M / (3.1 x 10^(-2) mol/L-atm)
To calculate this value, we need to convert the units to be consistent. We have the concentration in mol/L and the Henry's Law constant in mol/L-atm. Therefore, the units will cancel out.
P = 0.25 M / (3.1 x 10^(-2) mol/L-atm)
P = 8.06 atm
Therefore, the pressure necessary to have a 0.25 M solution of CO2 is approximately 8.06 atmospheres.