How you Find the number of liters of hydrogen gas in 20 g of hydrogen at STP?

First find moles hydrogen gas.

20 grams H2 (1 mole H2/2.016 grams)

= 9.921 moles H2

Now, the ideal gas equation.

PV = nRT

(1 atm)(volume L) = (9.921 moles H2)(0.08206 L*atm/mol*K)(298.15 K)

Volume of hydrogen gas = 243 Liters

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