Helium is mixed with oxygen gas for deep-sea divers. Calculate the percent by volume of oxygen gas in the mixture if the diver has to submerge to a depth where the total pressure is 4.7 atm. The partial pressure of oxygen is maintained at 0.20 atm at this depth.

To calculate the percent by volume of oxygen gas in the mixture, we need to use the concept of partial pressure.

The partial pressure of a gas is the pressure that the gas would exert if it occupied the same volume alone (at the same temperature). In this case, the partial pressure of oxygen is given as 0.20 atm.

The total pressure of the mixture is 4.7 atm.

To calculate the percent by volume of oxygen gas, we can express it as a ratio of the partial pressure of oxygen to the total pressure:

Percent by volume of oxygen = (Partial pressure of oxygen / Total pressure) * 100

Substituting the given values:

Percent by volume of oxygen = (0.20 atm / 4.7 atm) * 100

Calculating this expression:

Percent by volume of oxygen ≈ 4.26%

Therefore, the percent by volume of oxygen gas in the mixture is approximately 4.26%.