Final answer:
To determine the amount of hydrogen in kilograms present in a car's hydrogen tank, one must utilize the ideal gas law to calculate moles, convert moles to grams using molar mass, and then convert grams to kilograms.
Step-by-step explanation:
To calculate how many kilograms of hydrogen a car's tank holds when full, we can use the ideal gas law, which is PV = nRT, where P is pressure, V is volume, n is the amount of substance (moles), R is the ideal gas constant, and T is the temperature in Kelvins. The pressure of the tank is given as 5.25x105 torr, which needs to be converted to atmospheres as the gas constant R is typically expressed as 0.0821 Latm/molK. The volume is 141 L and the temperature is 25°C (298K).
Firstly, we convert the pressure to atmospheres: 5.25x105 torr / 760 torr/atm = 691.45 atm. Now we can use the ideal gas law to solve for n, the number of moles of hydrogen. After finding the number of moles, we can convert this to mass using the molar mass of hydrogen, which is 2.016 g/mol. Finally, we convert the grams to kilograms to get the desired unit of mass.