If 2.0 grams of hydrogen gas was occupied at STP, determine the volume in cubic meters.

Expert Answers
jerichorayel eNotes educator| Certified Educator

To solve this problem, the Ideal gas equation is important. Remember that the ideal gas law states that:

`PV = nRT`

to solve for the volume of Hydrogen gas, we can arrange the equation into:

`V = (nRT)/(P)`


Mass `H_2` = 2.0 grams

P = 0.986 atm (at STP)

T = 273.15 K (at STP)

R = gas constant = 0.08206 `(atm-L)/(mol-K)`

First, we get the number of moles of Hydrogen gas. 

`(2.0 grams H_2)* (1 mol e H_2)/(2.016 grams H_2)`

= 0.9921 moles `H_2`

Now we are ready to get the value of the volume.

V = (nRT)/(P)

V = (0.9921*0.08206*273.15)/(0.986atm)

V = 22.6 Liters of `H_2`  


The unit of volume can be expressed in many ways. I can also be equal to:

22600 mL; 22600`cm^3` ; 0.0226 cubic meters


note: There are many interpretations of STP, some would say that at STP, the condition of a gas is at 1atm (not 0.986at,) and 273.15 K.