Calculating the Percentage Composition by Weight of a Compound

Understanding the percentage composition by weight of elements in a compound is a fundamental concept in chemistry. This article will walk through the steps needed to determine the percentage composition of a compound by weight, specifically, a sample of a compound containing both oxygen and boron. We will use the example of a 0.24 g sample of a compound that contains 0.096 g of boron and 0.144 g of oxygen.

Introduction to Percentage Composition by Weight

The percentage composition by weight of an element in a compound represents the weight of that element per 100 grams of the compound. This is a crucial measurement as it provides a standardized way to express the proportion of each element within a compound.

Steps to Calculate Percentage Composition

Let's analyze the sample step by step to calculate the percentage composition of boron and oxygen in the compound.

Step 1: Determine the Weight of Each Element in the Compound

We are given the following data:

Total weight of the compound: 0.24 g Weight of boron (B): 0.096 g Weight of oxygen (O): 0.144 g

Step 2: Use the Formula to Find the Percentage Composition

The formula to find the percentage composition by weight of an element is:

Percentage composition of element (Weight of element / Total weight of compound) × 100

Applying this formula, we can calculate the percentage composition of boron and oxygen as follows:

Percentage of Boron

Using the formula:

Percentage of boron (0.096 / 0.24) × 100

Percentage of boron 0.4 × 100 40%

Percentage of Oxygen

Using the formula:

Percentage of oxygen (0.144 / 0.24) × 100

Percentage of oxygen 0.6 × 100 60%

Alternative Methods to Calculate Weight Percentage

We can also express the weight of an element per gram of the compound and then multiply by 100:

Step 1: Calculate the Weight of the Element Per Gram of Compound

Boron:

Weight of boron per gram of compound 0.096 / 0.24 0.4 g

Oxygen:

Weight of oxygen per gram of compound 0.144 / 0.24 0.6 g

Step 2: Convert to Percentage

Percentage of boron 0.4 × 100 40%

Percentage of oxygen 0.6 × 100 60%

Conclusion

To summarize, the percentage composition of the compound containing 0.096 g of boron and 0.144 g of oxygen (total 0.24 g) is:

Boron (B): 40% Oxygen (O): 60%

Alert

Remember to apply this method consistently across all chemical compounds to ensure accurate results. Understanding the percentage composition by weight is essential for various applications, including stoichiometry and chemical analysis.

Keywords: percentage composition, boron, oxygen, weight calculation