The molecular formula of aspartame, the artificial sweetener marketed as NutraSweet®, is C14H18N2O5.

Question

What is the molar mass of aspartame?Express your answer using four significant figures.

How many moles of aspartame are present in 1.00 mg of aspartame?Express your answer using three significant figures.

How many molecules of aspartame are present in 1.00 mg of aspartame?
Express your answer using four significant figures.

How many hydrogen atoms are present in 1.00 mg of aspartame?Express your answer using three significant figures.

Answer 1

Latika,

 

This is a highly useful exercise in converting molar mass in grams to moles (which equates to 6.022x10^23 molecules according to Avogadro).

 

First we find the molar mass of Nutrasweet by looking up the molar mass of C (carbon), H (hydrogen), O (oxygen) and N (nitrogen) on a periodic table and multiply appropriately.

14*12.01+18*1.008+2*14.01+5*16=168.14+18.144+28.02+80=294.304g per mole aspartame

Now let's convert 1mg aspartame to moles:

1 mg * 1 g                            1 mole

          ----------- = .001 g *  ------------ = 3.398x10^-6 moles (yes these will be small amounts!)

           1000 mg                     294.304g

 

Now we can convert it to molecules:

3.398*10^-6 moles * 6.022*10^23 molecules

                                -------------------------- = 2.0462*10^18 molecules aspartame

                                 1 mole

 

Now each molecule aspartame has 18 atoms of hydrogen so multiply that above number by 18:

3.6833*10^19 atoms hydrogen

 

Make sure to count out the decimal places right here!