At STP how many moles of

argon gas are present in 6.5

liters of argon gas

In order to determine the number of moles of the given volume of Ar, divide the given volume by the molar volume of an ideal gas,  

22.710 L/mol

Explanation:

So you have a volume of  6 .5

6.5L / 22.710 L/mol

L is eliminate .

6.5/ 22.710 L/mol = 0.286 mol

Using the older STP values of  0 ∘ C  or  273.15 K , and pressure of  1 atm , molar volume is  22.414 L/mol .

6.5L /22.414 L/mol .= 0.289 mol

c, liquids evaporate, creating a gas