Question

What is the molar mass of ethanol (C2H5OH) in g/mol? (Answer to three decimal places.) Use the following atomic masses to solve:

a) 45.067 g/mol
b) 61.053 g/mol
c) 46.069 g/mol
d) 63.039 g/mol

Answer 1

The molar mass of ethanol (C2H5OH) is 46.069 g/mol, which is the sum of the molar masses of each atom in the molecule.

Step-by-step explanation:

To calculate the molar mass of ethanol, denoted as C2H5OH or C2H6O, we can sum up the atomic masses of all the atoms present in the molecule:

• 2C: (2 atoms)(12.011 g/mol per atom) = 24.022 g/mol
• 6H: (6 atoms)(1.0079 g/mol per atom) = 6.0474 g/mol
• 1O: (1 atom)(15.9994 g/mol per atom) = 15.9994 g/mol

Add these values together to find the molecular mass of ethanol:

24.022 g/mol + 6.0474 g/mol + 15.9994 g/mol = 46.069 g/mol

The molar mass of ethanol is thus 46.069 g/mol, which we can round to three decimal places as required.