An open flask sitting in a lab fridge looks empty, but we know that actually it

Question

An open flask sitting in a lab fridge looks empty, but we know that actually it is filled with a mixture of gases called air. If the volume is 1.50 Liters, and the air is at standard temperature and pressure, how many gaseous molecules does the flask contain? An open flask sitting in a lab fridge looks empty, but we know that actually it is filled with a mixture of gases called air. If the volume is 1.50 Liters, and the air is at standard temperature and pressure, how many gaseous molecules does the flask contain?

Explanation / Answer

Since we are at standard temperature and pressure, we can use molar volume: Vm = 22.4 L

pVm=nRT

p=1 atm, n=1 mol, R= 0.08206 L atm mol-1 K-1, T= 273 K
Vm= (1 mol x 0.08206 L atm mol-1 K-1 x 273 K)/1 atm = 22.4 L

no. of moles, n= V/Vm= 1.50 L /22.4 Lmol-1 = 0.066922 mol

therefore, no. of gas moleules = n x Avogadro's number

= 0.066922 mol x 6.022 x 1023 molecules mol-1 = 4.03 x 1022 molecules

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.