Answer:
128.2 moles
Step-by-step explanation:
Data Given:
Amount of ethanol (C₂H₅OH) = 6.5 lbs/ gal
moles of ethanol (C₂H₅OH) = ?
Solution:
As we have 6.5 lbs per gallon, So, 2 gallons will have total amount of ethanol (C₂H₅OH) will be
Total amount of (C₂H₅OH) will be = 2 x 6.5 lbs
Total amount of (C₂H₅OH) will be = 13 lbs
Now,
Convert lb to grams
1 lb = 453.6
13 lbs = 13 x 453.6 = 5897 g
So, we have 5897 g of ethanol.
Now we have to find number of moles, for which formula will use
no. of moles = mass in grams / molar mass
Molar mass of C₂H₅OH = 2(12) + 5(1) + 16 + 1
Molar mass of C₂H₅OH = 24 + 5 + 16 + 1
Molar mass of C₂H₅OH = 46 g/mol
Put values in the above formula
no. of moles = 5897 g / 46 g/mol
no. of moles = 128.2 moles
no. of moles of ethanol = 128.2 moles