Molar Mass and Chemical Formulas

The video tutorial explains how to calculate the molar mass of ammonium sulfide (NH4₂S). It begins by identifying the components of NH4₂S, then uses the periodic table to find the atomic masses of nitrogen, hydrogen, and sulfur. The tutorial demonstrates the calculation process, including multiplying the ammonium ion mass by two and adding the sulfur mass. The final molar mass is calculated as 66.13 grams per mole. The video concludes with an explanation of what this molar mass means in practical terms.

What is the chemical formula for ammonium sulfide?

• (NH3)2S

• NH4S2

• (NH4)2S

• NH3S

What is the atomic mass of nitrogen as used in the calculation?

• 32.07 g/mol

• 1.01 g/mol

• 28.02 g/mol

• 14.01 g/mol

How many hydrogen atoms are present in one ammonium ion?

• Four

• Five

• Two

• Three

Why do we multiply the molar mass of the ammonium ion by 2?

• To convert to grams

• Because there are two ammonium ions

• To balance the equation

• Because there are two sulfur atoms

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

• 14.01 g/mol

• 1.01 g/mol

• 32.07 g/mol

• 36.10 g/mol

What is the final calculated molar mass of ammonium sulfide?

• 36.10 g/mol

• 32.07 g/mol

• 66.13 g/mol

• 14.01 g/mol

What does the molar mass of 66.13 g/mol represent?

• The mass of one atom of ammonium sulfide

• The mass of one mole of ammonium sulfide

• The mass of one mole of nitrogen

• The mass of one molecule of sulfur

If you have 66.13 grams of ammonium sulfide, how many moles do you have?

• 0.5 moles

• 1 mole

• 2 moles

• 3 moles

What might cause a slight difference in the calculated molar mass?

• Using a different periodic table

• Using a different calculator

• Incorrect calculation

• Different chemical formula