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Safarl File Edit View History Bookmarks Window Help 84% Thu Dec 7 8:34 PM MyLVC ter 10 SmartWork 27% 12/08/17 Thisis a Mixed question / It is worth 2 points/You have 4 of 4 attempts remaining/There is no attempt po 07 Question (2 points) Q See page 454 Radon is a naturaly occurring radioactive gas found in the ground and in building materials. t is easily inhaled and emits alpha particles when it decays. Cumulative radon exposure is a significant risk factor for lung cancer. 1st attempt Part 1 (1 point) lad See Periodic Table Calculate the density of radon at 305 K and 0.900 atm of pressure. g/L 3 OF 9 QUESTIONS COMPLETED K 07/09> 2 MacBook

Explanation / Answer

Gas is radon gas (Rn) , Pressure is 0.9 atm, Temperature is 305 °K

Let's start with the Ideal Gas Law formula.

PV = nRT

{ where,P = pressure,V = volume,n = number of moles of gas,R = Gas constant (0.0821 L·atm/mol·K), T = absolute temperature }

If we solve the equation for volume, we get:

V = (nRT)/P

We know everything we need to find the volume now except the number of moles of gas. To find this, remember the relationship between number of moles and mass.

n = m / MM

{ where, n = number of moles of gas, m = mass of gas, MM = molecular mass of the gas }

This is helpful since we needed to find the mass and we know the molecular mass of radon gas. If we substitute for n in the first equation, we get:

V = (mRT)/(MMP)

Divide both sides by m:

V/m = (RT)/(MMP)

But density is m/V, so flip the equation over to get:

m/V = (MMP)/(RT) = density of the gas.

Now we need to insert the values we know.

MM of radon gas or Rn is = 222.018 grams/mole

m/V = (222.018 g/mol · 0.9 atm) / (0.0821 L·atm/mol·K · 305 K)

m/V = 7.98

density = mass / volume = 7.98 g/L

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