Combined gas law problem: A balloon is filled with 500.0 mL of helium at a temperature of 27°Cand 755 mm Hg. As the balloon rises in the atmosphere, the pressure and temperature drop. What\·olume will it have when it reaches an altitude where the temperature is -33°C and the·pressure is0.65 atm'

Respuesta :

Answer

The volume will be 0.61 L or 610 mL

Explanation

Given:

Initial volume, V₁ = 500.0 mL = 0.5 L

Initial temperature, T₁ = 27 °C = (27 + 273.15) = 300.15 K

Initial pressure, P₁ = 755 mmHg = 0.993 atm

Final temperature, Tā‚‚ = -33 °C = 240.13 K

Final pressure, Pā‚‚ = 0.65 atm

What to find:

The final volume,, V.

Solution:

The combined gas law equation is given by:

[tex]\begin{gathered} \frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2} \\ \\ \end{gathered}[/tex]

Put the values of the parameters into the combined law equation:

[tex]\begin{gathered} \frac{0.993atm\times0.5L}{300.15K}=\frac{0.65atm\times V_2}{240.15\text{ }K} \\ \\ \frac{0.4965\text{ }atm.L}{300.15\text{ }K}=\frac{0.65atm\times V_2}{240.15\text{K}} \\ \\ Cross\text{ }multiply \\ \\ V_2\times0.65atm\times300.15\text{ }K=240.15K\times0.4965\text{ }atm.L \\ \\ V_2=\frac{240.15K\times0.4965\text{ }atm.L}{0.65atm\times300.15K} \\ \\ V_2=0.611\text{ }L \end{gathered}[/tex]

The volume will be 0.61 L or 610 mL