A mixture of nitrogen (N₂) and helium has a volume of 365 mL at 30 °C and a total pressure of 745 mmHg. (8.5, 8.6, 8.7)
a. If the partial pressure of helium is 65 mmHg, what is the partial pressure of the nitrogen?

At a restaurant, a customer chokes on a piece of food. You put your arms around the person's waist and use your fists to push up on the person's abdomen, an action called the Heimlich maneuver.

b. Why does it cause the person to expel the food item from the airway?

In 1783, Jacques Charles launched his first balloon filled with hydrogen gas, which he chose because it was lighter than air. If the balloon had a volume of 31 000 L, how many kilograms of hydrogen were needed to fill the balloon at STP?

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A weather balloon is partially filled with helium to allow for expansion at high altitudes. At STP, a weather balloon is filled with enough helium to give a volume of 25.0 L. At an altitude of 30.0 km and –35 ⁰C, it has expanded to 2460 L. The increase in volume causes it to burst and a small parachute returns the instruments to Earth.

b. What is the final pressure, in millimeters of mercury, of the helium inside the balloon when it bursts?

What is the total pressure, in millimeters of mercury, of a gas mixture containing argon gas at 0.25 atm, helium gas at 350 mmHg, and nitrogen gas at 360 Torr?