How many molecules of CH3 COOH are contained within 43.4 g of acetic acid?

Question

How many molecules of CH

Answer 1

In case you weren't already aware, CH₃COOH is the chemical formula for Acetic Acid. To find the relationship between mass and molecules we will have to do two unit conversions.

First, to find the molar mass of acetic acid, we'll add the molar mass of each of the elements in CH₃COOH:

2C = 12.011 g/mol * 2 = 24.022 g/mol

+

4H = 1.008 g/mol *4 = 4.032 g/mol

+

2O = 15.999 g/mol*2 = 31.998 g/mol

=

60.052 g/mol of Acetic Acid

Then we will convert the mass of Acetic Acid (43.4 grams) to moles using the molar mass of CH₃COOH:

43.4 g * 1 mol/60.052 g = 0.723 mol of Acetic Acid

(Rounded to 3 significant figures)

Finally we will convert from moles to molecules with Avogadro's number:

0.723 mol * 6.02x10²³ molecules/mol = 4.35x10²³ molecules of Acetic Acid

(Rounded to 3 significant figures)

For unit conversions, keep in mind that units need to cancel out. This is a good way to double check that your conversions are correctly set up.