When 9.6 grams of NaBr are dissolved in enough water to create a 165-gram solution, what is the solution's concentration, expressed as a percent by mass?
4.8% NaBr
5.5% NaBr
5.8% NaBr
6.2% NaBr
To find the solution's concentration, expressed as a percent by mass, you need to calculate the mass of NaBr in the solution and then divide it by the mass of the solution.
Given:
Mass of NaBr = 9.6 grams
Mass of solution = 165 grams
Step 1: Calculate the mass of NaBr in the solution.
To find the mass of NaBr in the solution, you simply subtract the mass of the pure solvent from the total mass of the solution.
Mass of NaBr in the solution = Mass of solution - Mass of solvent
The mass of the solvent is the difference between the total mass of the solution and the mass of NaBr.
Mass of solvent = Mass of solution - Mass of NaBr
Mass of solvent = 165 grams - 9.6 grams
Mass of solvent = 155.4 grams
Now, you can calculate the mass of NaBr in the solution.
Mass of NaBr in the solution = Mass of solution - Mass of solvent
Mass of NaBr in the solution = 165 grams - 155.4 grams
Mass of NaBr in the solution = 9.6 grams
Step 2: Calculate the percentage concentration by mass.
To find the concentration as a percentage, you divide the mass of NaBr in the solution by the mass of the solution and multiply by 100.
Percentage concentration by mass = (Mass of NaBr in the solution / Mass of solution) * 100
Percentage concentration by mass = (9.6 grams / 165 grams) * 100
Percentage concentration by mass = 5.81818182 * 100
Percentage concentration by mass ≈ 5.8%
Therefore, the concentration of the solution, expressed as a percent by mass, is 5.8% NaBr.
To find the solution's concentration, expressed as a percent by mass, you need to divide the mass of the solute (NaBr) by the mass of the solution and multiply by 100.
First, calculate the mass of the solute (NaBr), which is 9.6 grams.
Next, calculate the mass of the solution, which is the sum of the mass of the solute (9.6 grams) and the mass of the solvent.
The mass of the solvent can be found by subtracting the mass of the solute from the total mass of the solution:
Mass of solvent = Total mass of solution - Mass of solute
Mass of solvent = 165 grams - 9.6 grams
Mass of solvent = 155.4 grams
Now, calculate the concentration (percent by mass):
Concentration = (Mass of solute / Mass of solution) × 100
Concentration = (9.6 grams / 165 grams) × 100
Concentration ≈ 5.818%
Therefore, the solution's concentration, expressed as a percent by mass, is approximately 5.818%. Rounded to one decimal place, it would be 5.8% NaBr.