Bacteria and viruses are inactivated by temperatures above 145 °C in an autoclave. An autoclave contains steam at 1.00 atm and 100 °C. • At what pressure, in atmospheres, will the temperature of the steam in the autoclave reach 145 °C, if n and V do not change?

Question

Express the pressure to three significant figures and include the appropriate units.

Answer 1

To solve this problem, we can use the ideal gas law:

PV = nRT

Where:
P = pressure (in atm)
V = volume (in liters)
n = number of moles
R = ideal gas constant (0.0821 L·atm/(mol·K))
T = temperature (in Kelvin)

First, we need to convert the temperatures to Kelvin:
100 °C + 273.15 = 373.15 K
145 °C + 273.15 = 418.15 K

Since n and V do not change, we can set up a ratio between the initial and final pressures:

P1/T1 = P2/T2

Plugging in the values:
1.00 atm / 373.15 K = P2 / 418.15 K

Now we can solve for P2:

P2 = (1.00 atm / 373.15 K) * 418.15 K
P2 = 1.12 atm

Therefore, at a temperature of 145 °C, the pressure in the autoclave will be approximately 1.12 atm.