You calculate the percentage by mass of glucose in a sugar solution by dividing the mass of the glucose by the total mass of the solution (glucose plus solvent), and then multiplying by 100%.
Here's a breakdown of the process:
1. Define Key Terms:
- Solute: The substance being dissolved (in this case, glucose).
- Solvent: The substance doing the dissolving (typically water in sugar solutions).
- Solution: The mixture formed when the solute dissolves in the solvent.
2. The Formula:
The formula for calculating the percentage by mass of glucose is:
Percentage by mass of glucose = (Mass of glucose / Mass of solution) * 100%
3. Steps:
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Determine the mass of glucose (solute). This will be given in the problem or you may need to measure it. The mass unit is typically in grams (g).
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Determine the mass of the solution. This is the total mass of the glucose and the solvent (usually water). This may be given directly, or you may need to calculate it by adding the mass of the glucose to the mass of the solvent. Again, the mass unit is typically in grams (g).
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Apply the formula. Divide the mass of the glucose by the mass of the solution.
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Multiply by 100%. This converts the result into a percentage.
4. Example:
Let's say you have a sugar solution made by dissolving 25 grams of glucose in 100 grams of water.
- Mass of glucose = 25 g
- Mass of water = 100 g
- Mass of solution = Mass of glucose + Mass of water = 25 g + 100 g = 125 g
Percentage by mass of glucose = (25 g / 125 g) 100% = 0.20 100% = 20%
Therefore, the percentage by mass of glucose in the sugar solution is 20%.
In summary, the percentage by mass calculation quantifies the concentration of glucose in a solution, expressing it as a percentage of the total solution mass.
