Question

A gas sample occupies a volume of 18. 86 L when the temperature is 35. 2 oC and the pressure is 735. 5 torr. How many moles of gas are there in the sample?

Answer 1

We can use the ideal gas law to solve for the number of moles of gas:

PV = nRT

where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature in Kelvin.

First, we need to convert the temperature from Celsius to Kelvin:

T = 35.2 + 273.15 = 308.35 K

Next, we need to convert the pressure from torr to atm (since R is in units of atm·L/mol·K):

P = 735.5 torr / 760 torr/atm = 0.966 atm

Now we can plug in the values and solve for n:

n = (PV)/(RT) = (0.966 atm * 18.86 L) / (0.08206 L·atm/mol·K * 308.35 K) ≈ 0.801 moles

Therefore, there are approximately 0.801 moles of gas in the sample.