A sample of hydrogen with a volume of 800mL exerts a pressure of 620 mm HG at 5 degrees. What volume will it occupy at STP?

Answer 1

To determine the volume of hydrogen at STP (standard temperature and pressure), we first need to convert the given pressure to the units typically used for STP, which are atmospheres (atm) and Kelvin (K).

1 atm = 760 mm Hg
1 atm = 101.3 kPa
1 atm = 101.3 J/cm^3

Given pressure = 620 mm Hg
Pressure in atm = 620 mm Hg * (1 atm / 760 mm Hg) = 0.8163 atm

Now we can use the ideal gas law, PV = nRT, to solve for the volume of hydrogen at STP.

P1V1 / T1 = P2V2 / T2

Since the initial temperature (5 degrees Celcius) is not at Kelvin, we need to convert it to Kelvin:
T1 = 5 + 273 = 278 K
T2 = 273 K (STP temperature)

Now we can rearrange the equation to solve for V2:

V2 = (P1V1 * T2) / (P2 * T1)
V2 = (0.8163 atm * 800 mL * 273 K) / (1 atm * 278 K)
V2 = 659.378 mL

Therefore, the volume of hydrogen at STP would be 659.378 mL.