Molecular Weight Calculations in Chemistry

The video tutorial explains how to calculate the molecular weight of NH3, also known as the molar mass. It begins by identifying the molar mass of nitrogen and hydrogen from the periodic table. The tutorial then demonstrates how to account for the three hydrogen atoms in NH3 by multiplying hydrogen's molar mass by three. Finally, it adds the results to find the total molar mass of NH3, which is 17.3 grams per mole.

What is the first step in finding the molecular weight of NH3?

• Divide the atomic weight of nitrogen by the number of hydrogen atoms.

• Multiply the atomic weight of hydrogen by three.

• Add the atomic weights of nitrogen and hydrogen.

• Look up the atomic weight of nitrogen on the periodic table.

How many hydrogen atoms are present in NH3?

• One

• Two

• Three

• Four

What is the atomic weight of nitrogen used in the calculation?

• 3.03 g/mol

• 17.3 g/mol

• 14.01 g/mol

• 1.01 g/mol

What is the final molecular weight of NH3?

• 1.01 g/mol

• 17.3 g/mol

• 14.01 g/mol

• 3.03 g/mol

What is the importance of performing multiplication before addition in the calculation?

• It reduces the number of steps required.

• It is a rule specific to chemistry calculations.

• It simplifies the calculation process.

• It ensures the correct order of operations is followed.