Question

Propane (C3H8) has a molar mass of 132 g/mole. You started out the day with a tank containing 9071 g of propane. At the end of the day, your tank contained 7532 g of propane gas. How many moles of gas did you use?

Answer 1

To solve this, first consider how many grams of propane you lost during the day. This can be seen by subtracting 9071 g by 7532 g. This gives a value of 1539 g. To get moles from this, remember that molar mass, 132, is in grams per mole. We have 1539 g of propane used, so to find this is mole, we can divide it by the molar mass 132 grams per mole.

1539 grams x 1 moles/132 grams

In this way, we can cancel out grams and be left with moles.

Answer:

11.66 moles of propane