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Chemistry Homework Help => AP Chemistry => Topic started by: sjhorsegirl on December 30, 2009, 03:07:23 PM

Title: Lab Questions: Determining the Gas Law Constant "R"
Post by: sjhorsegirl on December 30, 2009, 03:07:23 PM
At present, automobile batteries are sealed. When lead storage batteries discharge, they produce hydrogen. Suppose the void volume in the battery is 100 mL at 1 atm of pressure and 25 degrees Celsius. What would be the pressure increase if 0.05 g of Hydrogen were produced by the discharge of the battery? Does this present a problem? Do you know why sealed lead storage batteries were not used in the past?
Title: Re: Lab Questions: Determining the Gas Law Constant "R"
Post by: uma on January 02, 2010, 07:37:32 AM
You can use
PV = nRT
P = nRT / V
now you have n(number of moles of H2 ) , R = 0.0821 atm L /K .mol  and temp ( 25 + 273 )K ,
V is the volume = 100mL = 0.1L
new pressure = 1 atm + pressure due to H2
yes it can cause a problem because H2 is highly combustible gas and its formation in a sealed battery could lead to explosion.