A gas-filled weather balloon has a volume of 54.0 L at ground level, where the pressure is 759 mmHg and the temperature is [tex]$21.1^{\circ} C$[/tex]. After being released, the balloon rises to an altitude where the temperature is [tex]$-3.86^{\circ} C$[/tex] and the pressure is 0.0757 atm. What is the weather balloon's volume at the higher altitude?

[tex]V =[/tex]
[tex]\square[/tex]



Answer :

Certainly! Let's solve the problem step-by-step using the Combined Gas Law which relates pressure (P), volume (V), and temperature (T) of a gas sample with the equation:

[tex]\[ \frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2} \][/tex]

Here are the given values:
- Initial volume [tex]\( V_1 = 54.0 \)[/tex] L
- Initial pressure [tex]\( P_1 = 759 \)[/tex] mmHg
- Initial temperature [tex]\( T_1 = 21.1^{\circ} \text{C} \)[/tex]

First, we need to convert the initial temperature from Celsius to Kelvin:
[tex]\[ T_1 = 21.1 + 273.15 = 294.25 \text{ K} \][/tex]

Next, we are given the conditions at the higher altitude:
- Temperature [tex]\( T_2 = -3.86^{\circ} \text{C} \)[/tex]
- Pressure [tex]\( P_2 = 0.0757 \text{ atm} \)[/tex]

Again, convert the temperature [tex]\( T_2 \)[/tex] to Kelvin:
[tex]\[ T_2 = -3.86 + 273.15 = 269.29 \text{ K} \][/tex]

Also, convert the pressure [tex]\( P_2 \)[/tex] into mmHg (since 1 atm = 760 mmHg):
[tex]\[ P_2 = 0.0757 \times 760 = 57.532 \text{ mmHg} \][/tex]

Now, we are ready to solve for the new volume [tex]\( V_2 \)[/tex] using the Combined Gas Law:
[tex]\[ \frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2} \][/tex]

Rearranging the formula to solve for [tex]\( V_2 \)[/tex]:
[tex]\[ V_2 = \frac{P_1 V_1 T_2}{T_1 P_2} \][/tex]

Substituting the given values into the equation:
[tex]\[ V_2 = \frac{759 \,\text{mmHg} \times 54.0 \,\text{L} \times 269.29 \,\text{K}}{294.25 \,\text{K} \times 57.532 \,\text{mmHg}} \][/tex]

[tex]\[ V_2 = 651.97 \, \text{L} \quad \text{(rounded to two decimal places)} \][/tex]

Therefore, the volume of the weather balloon at the higher altitude is:
[tex]\[ V = 651.97 \, \text{L} \][/tex]