1.33*10^ 23 molecules of carbon dioxide to moles

0.22moles of carbon dioxide

Explanation:

Given parameters:

Number of molecules of carbon dioxide  = 1.33 x 10²³molecules

Unknown:

Number of moles   = ?

Solution:

To solve this problem, we use the relationship below:

   1 mole of a substance contains 6.02 x 10²³moleccules;

So;

    1.33 x 10²³molecules will contain   = 0.22moles of carbon dioxide

Total mass of the compound:=18.20+2.45

=20.65

Percentage by mass of hydrogen:=2.45÷20.65×100

=11.86%

Explanation:

Just follow the steps i have provided above