Question

What volume does 76 g of fluorine gas occupy at stp?

Answer 1

2 * 22.4 = 44.8 liters (if using pre 1982 standard) 2 * 22.7 = 45.4 liters (if using 1982 and later standard) First, let's determine how many moles of F2 we have. Atomic weight fluorine = 18.998403 Molar mass F2 = 2 * 18.998403 = 37.996806 g/mol Moles F2 = 76 g / 37.996806 g/mol = 2.000168119 mol Now we have a minor problem. What definition of STP are you using? Up until 1982, STP was defined as 0°C and 1 atmosphere (101.325 kPa) From 1982 and later, STP was defined as 0°C and 100 kPa Because of the difference in pressure between the two different definitions of STP, the molar volume of a gas is 22.414 liter/mol using the pre-1982 definition and 22.711 liter/mol using the 1982 and later definition. So you get to choose which of the following 2 answers. 2 * 22.4 = 44.8 liters (if using pre 1982 standard) 2 * 22.7 = 45.4 liters (if using 1982 and later standard) Unfortunately there's still a large number of text books in use using the standard that should have been obsolete 35 years ago.