Question

How many moles of an ideal gas is contained in a cylinder with a volume of 137 mL, a pressure of 52.0 cm of Hg and a temperature of 98 degrees Fahrenheit? SHOW WORK!

Answer 1

Answer: The number of moles of ideal gas are 0.0037 moles

Explanation:

To calculate the mass of helium gas, we use the equation given by ideal gas:

PV = nRT

where,

P = Pressure of helium gas = 52 cmHg = 520 mm Hg    (Conversion factor: 1 cm = 10 mm)

V = Volume of the helium gas = 137 mL = 0.137 L   (Conversion factor: 1L = 1000 mL)

n = number of moles of gas = ?

R = Gas constant = $62.3637\text{ L.mmHg }mol^{-1}K^{-1}$

T = Temperature of helium gas = $98^oF=309.817K$    (Conversion factor: $(T(K)-273.15)=(T(^oF)-32)\times \frac{5}{9}$  )

Putting values in above equation, we get:

$520mmHg\times 0.137L=n\times 62.3637\text{ L.mmHg }mol^{-1}K^{-1}\times 309.817K\\\\n=0.0037mol$

Hence, the number of moles of gas is 0.0037 moles.