Final answer:
To calculate the number of liters in 5.43x10^25 molecules of H2, use Avogadro's number and the molar volume of a gas at STP to convert the number of molecules to moles and then to liters.
Step-by-step explanation:
To calculate the number of liters in 5.43x1025 molecules of H2, we can use the Avogadro's number and the molar volume of a gas at STP. Avogadro's number is approximately 6.022 x 1023 molecules per mole, and the molar volume of a gas at STP is 22.4 liters per mole. We can set up a dimensional analysis to find the number of moles, and then multiply by the molar volume to find the volume in liters.
Step 1: Convert the given number of molecules to moles using Avogadro's number. 5.43x1025 H2 molecules x (1 mole H2 / 6.022 x 1023 H2 molecules) = 9.02 moles H2
Step 2: Multiply the number of moles by the molar volume at STP. 9.02 moles H2 x (22.4 liters / 1 mole) = 202.35 liters H2