How many grams are in 5.12 moles of Al

Explanation:

To convert from moles to grams, we must use molar mass.

This can be found on the Periodic Table, so look for the symbol for aluminum: Al

We can use this number as a ratio.

Multiply by the given number of moles: 5.12

Multiply. The moles of aluminum will cancel.

Round. The original measurement of moles has 3 significant figures, so our answer must also have 3 sig figs.

For the number we calculated, that is the ones place. The 1 in the tenth place tells us to leave the 8.

There is about 138 grams of aluminum in 5.12 moles.