Percent Composition and Atomic Mass in H2S

The video tutorial explains how to calculate the percent composition by mass of each element in hydrogen sulfide (H2S). It begins with an introduction to the concept of percent composition. The tutorial then details the calculation process for hydrogen, using its molar mass and the number of atoms in H2S. The same process is applied to sulfur, and the results are verified to ensure they sum to approximately 100%. The video concludes with a brief summary of the calculations.

What is the first step in finding the percent composition by mass for an element in a compound?

• Calculate the molar mass of the compound.

• Find the atomic mass of the element from the periodic table.

• Multiply the atomic mass by the number of atoms.

• Determine the number of atoms of the element in the compound.

How do you calculate the contribution of hydrogen to the percent composition in H2S?

• Add the atomic masses of hydrogen and sulfur.

• Multiply the atomic mass of hydrogen by the number of hydrogen atoms and divide by the molar mass of H2S.

• Divide the atomic mass of hydrogen by the molar mass of H2S.

• Multiply the atomic mass of hydrogen by the number of sulfur atoms.

What is the percent composition of hydrogen in H2S?

• 5.93%

• 94.07%

• 1.01%

• 50%

What is the atomic mass of sulfur used in the calculation for H2S?

• 1.01 g/mol

• 32.07 g/mol

• 34.09 g/mol

• 2.02 g/mol

How many sulfur atoms are present in H2S?

• One

• Two

• Three

• None

What is the percent composition of sulfur in H2S?

• 32.07%

• 5.93%

• 50%

• 94.07%

What should the sum of the percent compositions of hydrogen and sulfur in H2S be?

• 5.93%

• 100%

• 50%

• 94.07%