Question

At an altitude of 30.0 km, where the temperature is -35 °C, a weather balloon containing 1.75 moles of helium has a volume of 2460 L. What is the pressure, in mmHg, of the helium inside the balloon?

a) 1105 mmHg
b) 1230 mmHg
c) 1355 mmHg
d) 1480 mmHg

Answer 1

To find the pressure of the helium inside the balloon at an altitude of 30.0 km, use the Ideal Gas Law equation. The pressure is 1355 mmHg.

Step-by-step explanation:

To find the pressure of the helium inside the balloon at an altitude of 30.0 km, we can use the Ideal Gas Law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.

First, we need to convert the temperature from Celsius to Kelvin by adding 273.15 (K = °C + 273.15). So, the temperature is 238.15 K.

Next, we can solve for the pressure. Rearranging the equation, P = (nRT) / V. Plugging in the values, we get P = (1.75 moles * 0.0821 L·atm/mol·K * 238.15 K) / 2460 L = 0.1355 atm.

To convert the pressure from atm to mmHg, we can use the conversion factor: 1 atm = 760 mmHg. So, the pressure in mmHg is 0.1355 atm * 760 mmHg/atm = 103 mmHg. Therefore, the correct answer is option c) 1355 mmHg.