Chemistry - Calculating the Empirical Formula of a Compound!

This video tutorial explains how to calculate the empirical formula of a compound in four steps: percent to grams, grams to moles, divide by small, and multiply to a whole. It begins with an introduction to empirical formulas and their importance, followed by a demonstration of simplifying molecular formulas. Two example problems are provided to illustrate the process, one involving carbon, hydrogen, and oxygen, and the other involving magnesium and nitrogen.

What is the primary purpose of an empirical formula?

• To show the exact number of atoms in a molecule

• To represent the simplest whole number ratio of elements in a compound

• To provide the molecular weight of a compound

• To determine the physical state of a compound

Which of the following is NOT one of the four steps to calculate an empirical formula?

• Divide by large

• Grams to moles

• Percent to grams

• Multiply to a whole

In the first example, what is the assumed mass of the sample used to convert percent to grams?

• 100 grams

• 150 grams

• 50 grams

• 200 grams

What is the empirical formula derived from the first example problem?

• CH2O

• C2H4O2

• CHO

• C6H12O6

In the second example, what is the first step in finding the empirical formula?

• Convert grams to moles

• Convert percent to grams

• Divide by the smallest number of moles

• Multiply to a whole number

What is the empirical formula for the compound consisting of 72.2% magnesium and 27.8% nitrogen?

• MgN2

• Mg3N2

• Mg2N3

• MgN

If the smallest number of moles in a calculation is 1.984, what should you do next?

• Convert back to grams

• Multiply by a factor to reach a whole number

• Divide by the largest number of moles

• Round to the nearest whole number