Answer: The temperature of the gas is 132.25K and -140.75°C
Step-by-step explanation:
Given that:
Volume of helium gas (V) = 18.5L
Temperature of helium gas (T) = ?
Pressure (P) = 0.85 atm
Number of moles (n) = 1.45 moles
Molar gas constant (R) is a constant with a value of 0.082 atm L K-1 mol-1
Then, apply the formula for ideal gas equation
pV = nRT
0.85atm x 18.5L = 1.45 moles x 0.082 atm L K-1 mol-1 x T
15.725 atm•L = 0.1189 atm•L•K-1 x T
T = 15.725 atm•L / 0.1189 atm•L•K-1
T = 132.25K
Given that temperature in Kelvin is 132.25, convert it to Celsius by subtracting 273
So, T(in Celsius) = 132.25K - 273
= -140.75°C
Thus, the temperature of the gas is 132.25K and -140.75°C