If you are given ethanol (C2H5OH) 6.5lbs / gal and you have 2 gallons how many moles do you have?

128.2 moles

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