Question

If you are given ethanol (C8H18) 6.3lbs/ gal and you have 12 gallons how many moles do you have? 

Answer 1

Answer:

745.5 moles

Explanation:

Data Given:

Amount of ethanol (C₂H₅OH) = 6.3 lbs/ gal

moles of ethanol (C₂H₅OH) = ?

Solution:

As we have 6.3 lbs per gallon, So, 2 gallons will have total amount of ethanol (C₂H₅OH) will be

Total amount of (C₂H₅OH) will be = 12 x 6.3 lbs

Total amount of (C₂H₅OH) will be = 75.6 lbs

Now,

Convert lb to grams

1 lb = 453.6

75.6 lbs = 75.6 x 453.6 = 34292 g

So, we have 34292 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 = 34292 g / 46 g/mol

                   no. of moles = 745.5 moles

no. of moles of ethanol = 745.5 moles