Molar Mass and Chemical Composition

The video tutorial explains how to calculate the molar mass of oxalic acid (H2C2O4). It begins by identifying the atomic masses of hydrogen, carbon, and oxygen from the periodic table. The tutorial then demonstrates how to calculate the contribution of each element to the total molar mass by multiplying the atomic mass by the number of atoms present in the compound. Finally, it sums these contributions to find the total molar mass of oxalic acid, explaining the significance of this value in terms of grams per mole.

What is the first step in calculating the molar mass of a compound like oxalic acid?

• Look up the atomic mass of oxygen.

• Determine the number of moles.

• Calculate the total mass directly.

• Find the atomic mass of hydrogen.

How many hydrogen atoms are present in oxalic acid (H2C2O4)?

• One

• Two

• Three

• Four

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

• 12.01 grams per mole

• 1.01 grams per mole

• 14.01 grams per mole

• 16.00 grams per mole

How many oxygen atoms are in a molecule of oxalic acid?

• Five

• Two

• Three

• Four

What is the total molar mass of oxalic acid as calculated in the video?

• 88.02 grams per mole

• 90.04 grams per mole

• 94.08 grams per mole

• 92.06 grams per mole

Why might the calculated molar mass differ slightly when using different periodic tables?

• Different measurement units.

• Because of rounding differences.

• Due to different atomic structures.

• Variations in chemical bonding.

What does the molar mass of 90.04 grams per mole signify for oxalic acid?

• It is the weight of one mole of oxalic acid.

• It is the weight of one liter of oxalic acid.

• It is the weight of one molecule of oxalic acid.

• It is the weight of one atom of oxalic acid.

If you have 90.04 grams of oxalic acid, how many moles do you have?

• 3 moles

• 1 mole

• 0.5 moles

• 2 moles