Molar Mass and Chemical Formulas

The video tutorial explains how to calculate the molar mass of hydrogen sulfide (H2S). It begins by identifying the atomic mass of hydrogen from the periodic table, which is 1.01 grams per mole, and multiplies it by two since there are two hydrogen atoms in H2S. Next, it adds the atomic mass of sulfur, which is 32.7 grams per mole. The final molar mass of H2S is calculated to be 34.9 grams per mole. The tutorial concludes by noting that different periodic tables may round atomic masses differently, which could slightly alter the result.

What is the chemical formula for hydrogen sulfide?

• HS2

• H2S

• H2O

• H2SO4

How many hydrogen atoms are present in a molecule of H2S?

• 1

• 2

• 4

• 3

What is the atomic mass of sulfur used in the calculation of H2S's molar mass?

• 1.01

• 16.00

• 32.7

• 35.45

What is the final calculated molar mass of H2S?

• 2.02 g/mol

• 32.7 g/mol

• 36.5 g/mol

• 34.9 g/mol

Why might there be slight differences in the calculated molar mass of H2S?

• Different periodic tables round atomic masses differently.

• The number of hydrogen atoms is incorrect.

• The calculation method is incorrect.

• Sulfur is not present in H2S.