Question

Based on the three formulas shown, use one of them to solve for the purple yellow and red box and explain how you did it.

Answer 1

P = 11.133 atm (purple)

T = -236.733 °C(yellow)

n = 0.174 mol(red)

Further explanation

Some of the laws regarding gas, can apply to ideal gas (volume expansion does not occur when the gas is heated),:

• Boyle's law at constant T, P = 1 / V
• Charles's law, at constant P, V = T
• Avogadro's law, at constant P and T, V = n

So that the three laws can be combined into a single gas equation, the ideal gas equation

In general, the gas equation can be written

`\large {\boxed {\bold {PV = nRT}}}`

where

P = pressure, atm

V = volume, liter

n = number of moles

R = gas constant = 0.08206 L.atm / mol K

T = temperature, Kelvin

To choose the formula used, we refer to the data provided

Because the data provided are temperature, pressure, volume and moles, than we use the formula PV = nRT

• Purple box

T= 10 +273.15 = 373.15 K

V=5.5 L

n=2 mol

`\tt P=(nRT)/(V)\\\\P=(2* 0.08205* 373.15)/(5.5)\\\\P=11.133~atm`

• Yellow box

V=8.3 L

P=1.8 atm

n=5 mol

`\tt T=(PV)/(nR)\\\\T=(1.8* 8.3)/(5* 0.08205)\\\\T=36.42~K=-236.733^oC`

• Red box

T = 12 + 273.15 = 285.15 K

V=3.4 L

P=1.2 atm

`\tt n=(PV)/(RT)\\\\n=(1.2* 3.4)/(0.08205* 285.15)\\\\n=0.174~mol`