An amount of 54.11 grams of pentane, c5h12 ,is equal to

You don’t specify what we are supposed to be converting grams of pentane to, but I’m guessing it’s moles

First you need to find the molar mass of pentane.

Molar mass of C is 12.01 and molar mass of H is 1.008.

12.01*5 +1.007*12 = 60.05 + 12.08 = 72.13 grams C5H12 per mole

54.11/72.13 = 0.75 moles C5H12

So your answer is 0.75 moles C5H12