The question, "How to calculate mass percentage of Na2SO4?" is a bit misleading. Mass percentage is not calculated for a compound like Na2SO4 (sodium sulfate), but rather for the elements within that compound. Therefore, let's rephrase it as "How to calculate the mass percentage of each element within Na2SO4?"
Here's how to calculate the mass percentage of each element (Sodium, Sulfur, and Oxygen) in sodium sulfate (Na2SO4):
Understanding Mass Percentage
Mass percentage is a way of expressing the concentration of an element within a compound. It shows the proportion of an element's mass compared to the total mass of the compound, expressed as a percentage.
Formula
The formula to calculate mass percentage is:
Mass percent of an element = (Mass of that element in compound / Molar mass of that compound) x 100
Calculating Mass Percentage in Na2SO4
Here's how to apply the formula using the molar masses of each element:
1. Determine the Molar Mass of Na2SO4:
- Molar mass of Na (Sodium) = 23.0 g/mol
- Molar mass of S (Sulfur) = 32.00 g/mol
- Molar mass of O (Oxygen) = 16.00 g/mol
Molar mass of Na2SO4 = (2 × 23.0) + 32.00 + (4 × 16.00) = 46 + 32 + 64 = 142 g/mol
2. Calculate Mass Percentages:
| Element | Mass in Na2SO4 (g) | Calculation | Mass Percent (%) |
|---|---|---|---|
| Sodium (Na) | 46 | (46 / 142) × 100 | 32.39 |
| Sulfur (S) | 32 | (32 / 142) × 100 | 22.54 |
| Oxygen (O) | 64 | (64 / 142) × 100 | 45.07 |
Summary of Results:
- Mass percent of sodium (Na) in Na2SO4: 32.39%
- Mass percent of sulfur (S) in Na2SO4: 22.54%
- Mass percent of oxygen (O) in Na2SO4: 45.07%
Key Points
- The mass percentages should total approximately 100% if done correctly. (32.39% + 22.54% + 45.07% = 100%)
- This method helps in understanding the composition of chemical compounds.
