An open flask sitting in a lab refrigerator looks empty, but it is actually filled with a mixture of gases called air. if the flask volume is 3.50 l, and the air is at standard temperature and pressure, how many gaseous molecules does the flask contain?

9.39 × 10²² molecules

Explanation:

We can find the moles of gases (n) using the ideal gas equation.

P . V = n . R . T

where,

P is the pressure (standard pressure = 1 atm)

V is the volume

R is the ideal gas constant

T is the absolute temperature (standard temperature = 273.15 K)

There are 6.02 × 10²³ molecules in 1 mol (Avogadro's number). Then,

the volume of fluid displaced would equal the volume of the gas. use a gas syringe - this is a laboratory instrument that can be used to withdraw a certain volume of gas from a closed system or to measure the volume of gas from a chemical reaction.