(e) Dalton’s Law
Challenge Question:
Ordinary air contains about 78% nitrogen,
21% oxygen, and small amounts of several other gases. As a diver descends, the pressure of the air he is breathing increases by about one atm for every 10 m of depth. Oxygen may become toxic and cause convulsions if it is breathed at a pressure above 1.4 atmospheres.
According to Dalton’s Law, at what depth should a SCUBA diver be concerned about oxygen toxicity if he is breathing ordinary air?
Discussion Points:
• Dalton’s Law states that the pressure exerted by a mixture of gases is equal to the sum of the pressures that would be exerted by the gases individually.
• Since air contains about 21% oxygen, so the pressure of oxygen at the surface is about
0.21 atmosphere.
Challenge Question:
Ordinary air contains about 78% nitrogen,
21% oxygen, and small amounts of several other gases. As a diver descends, the pressure of the air he is breathing increases by about one atm for every 10 m of depth. Oxygen may become toxic and cause convulsions if it is breathed at a pressure above 1.4 atmospheres.
According to Dalton’s Law, at what depth should a SCUBA diver be concerned about oxygen toxicity if he is breathing ordinary air?
Discussion Points:
• Dalton’s Law states that the pressure exerted by a mixture of gases is equal to the sum of the pressures that would be exerted by the gases individually.
• Since air contains about 21% oxygen, so the pressure of oxygen at the surface is about
0.21 atmosphere.