Question

A sample of Freon-12 (CF2Cl2) occupies 25.5 L at 298 K and 153.3 kPa. Find its volume at STP.

Answer 1

To find the volume of Freon-12 at STP, we use the combined gas law formula and the initial conditions to solve for the final volume. The resulting volume at STP is approximately 20.8 liters.

Step-by-step explanation:

To find the volume of Freon-12 at STP (standard temperature and pressure), we use the combined gas law. The combined gas law relates the initial pressure (P1), volume (V1), and temperature (T1) with the final pressure (P2), volume (V2), and temperature (T2):

P1V1/T1 = P2V2/T2

We are given the following initial conditions: P1 = 153.3 kPa, V1 = 25.5 L, and T1 = 298 K. STP conditions are P2 = 101.325 kPa (1 atm) and T2 = 273 K (0°C). Plugging our values into the combined gas law and solving for V2 gives us:

V2 = (P1 * V1 * T2) / (P2 * T1)

V2 = (153.3 kPa * 25.5 L * 273 K) / (101.325 kPa * 298 K)

V2 = 20.8 L (rounded to two significant figures)

The volume at STP for the Freon-12 is approximately 20.8 liters.

Answer 2

35.8 L
According to the combined gas law: pV=nRT
p=pressure
V=volume
T=temperature in Kelvin
R=the universal gas constant
n=number of moles of the gas

Rearranging the equation: n= pV/RT
n=(153.3kPa)(25.5L)/R(298K)= 13.1/R
At STP (standard temperature and pressure) p=100kPa and T=273.15K.

Rearranging the equation again: V=nRT/p V=[(13.1/R)(R)(273.15K)]/100kPa = 35.8L