A solution is made containing 4.6g of potassium chloride per 64.0g of water. What is the weight/weight % or percent by mass of the solute?

Question

Caleb Adams · Accepted Answer

The w/w% of KCl in the solution is 6.7%.

The weight/weight percent of a solute in solution is determined by dividing the mass of the solute by the total mass of the solution, which is the sum of the mass of the solute and the mass of the solvent. #"mass of solute"/"mass of solution"xx100="w/w%"# In this problem, the mass of the solute potassium chloride is 4.6 g. The mass of the solvent (water) is 64.0 g. The mass of the solution is #4.6 "g KCl"+64.0 "g H"_2"O"=68.6 "g solution"# Calculate the w/w% of KCl in the solution. #(4.6"g KCl")/(68.6 "g solution")xx100=6.7 "w/w% KCl"# (rounded to two significant figures)

Henry Antrim · Answer

undefined To calculate the weight/weight percent (or percent by mass) of the solute, divide the mass of the solute (potassium chloride) by the total mass of the solution (potassium chloride + water), and then multiply by 100.

Weight of solute (potassium chloride) = 4.6 g
Total mass of solution = 4.6 g (potassium chloride) + 64.0 g (water) = 68.6 g

Weight/weight percent of solute = (4.6 g / 68.6 g) * 100 ≈ 6.7%

Therefore, the weight/weight percent (or percent by mass) of the solute (potassium chloride) in the solution is approximately 6.7%.