a solution is prepared by dissolving 15.0 gram of sodium chloride in 200 gram of water. what is the mass by mass percentage of sodium chloride in the solution?
Answers
Answer:
15g made up to 200ml with water = 7.5% w/v
Explanation:
You’re looking for % w/w, so :
Total weight of solution = weight of solute + weight of solvent : (15 + 200)g = 215g
Weight of solute = 15g
So, %w/w = 15/215 = 6.976% or approx 7% w/w
If you were doing % w/v :
Assuming the addition of salt DOES NOT INCREASE SOLUTION VOLUME :
15g/200ml = 7.5% w/v
But this doesn’t hold true, as adding salt to water will increase the volume, but not by 1ml for 1g (more like 1ml for every 2g)
If you were doing this properly :
15g made up to 200ml with water = 7.5% w/v
Answer:
7%
Explanation:
Given :
- Mass of solute = Mass of sodium chloride = 15.0 grams
- Mass of solvent = Mass of water = 200 grams
To find :
- Mass by mass per cent of sodium chloride
Mass by mass per cent = mass of solute/Mass of solution × 100
Mass of solution = Mass of solute + Mass of solvent
Mass of solution = 15+200 = 215 grams
Mass by mass per cent = 15/215×100
Mass by mass per cent of sodium chloride = 6.97%
The mass by mass percent of sodium chloride is approximately equal to 7%
Mass percent of water = 100%-7% = 93%