A mixture of O2 and He is prepared for a scuba diver who is going to descend 200 ft below the ocean surface. At that depth, the diver breathes a gas mixture that has a total pressure of 7.00 atm. If the pressure of the O2 in the tank at 200 ft below the ocean surface is 1140 mmHg, what is the partial pressure of the He?
please help me i am completely lost
Ptotal = PHe + PO2.
Solve for PH3.
To determine the partial pressure of helium (He), we can use Dalton's Law of Partial Pressures, which states that the total pressure of a gas mixture is equal to the sum of the partial pressures of its individual components.
In this case, we are given that the total pressure (P_total) of the gas mixture at 200 ft below the ocean surface is 7.00 atm. We are also given the pressure of oxygen (P_O2) in the tank as 1140 mmHg.
Now, before we proceed, we need to ensure that the pressure values are in the same units. In this case, we will convert 1140 mmHg to atm by dividing it by 760 mmHg (since 1 atm = 760 mmHg).
P_O2 = 1140 mmHg / 760 mmHg/atm = 1.50 atm
Next, let's assign variables to the partial pressures of oxygen (P_O2) and helium (P_He).
P_O2 = 1.50 atm (given)
P_He = ? (unknown)
According to Dalton's Law of Partial Pressures, the total pressure (P_total) is equal to the sum of the partial pressures of all the components:
P_total = P_O2 + P_He
Substituting the given values:
7.00 atm = 1.50 atm + P_He
Next, isolate P_He by subtracting 1.50 atm from both sides of the equation:
P_He = 7.00 atm - 1.50 atm
P_He = 5.50 atm
So, the partial pressure of helium (He) in the mixture is 5.50 atm.