Happy Friday, everybody! Today’s chemistry is still deep, DEEEEP in mole territory.

Ethanol ( C₂H₅OH) a domestically produced fuel source, is often blended with gasoline. A sample of ethanol has a mass of 45.6 grams.

a. How many carbon atoms does the sample contain?

b. How many hydrogen atoms are present?

c. How many oxygen atoms are present?

These are three “three-step” problems.

1. Find molar mass of the compound (using the Periodic Table) and then change grams of ethanol to moles of ethanol.
2. Change moles of EtOH (Ethanol’s abbreviation) into molecules of EtOH using Avogadro’s number.
3. Finally, multiply your number of molecules by each element’s subscript to find the atom’s of each.

Be especially careful of hydrogen. It’s a bit tricky. We write ethanol as C₂H₅OH because the “-OH” shows that it has an alcohol portion to the molecule, so it gives a chemist additional information just by writing the formula this way.

I will try to send yesterday’s answers in Remind even as you are taking a picture of today’s work and sending it to me in Remind. Show all your work.

Stay healthy and stay breezy!

T. Brown