Find final concentration of this new solution.

Question: Radhika made a solution by dissolving 40 g of salt in 100 g of water. Her friend, Saloni took 50 g solution from the solution prepared by Radhika and added 5 g more salt to it. Find the final concentration (w/w%) of this new solution.

Solution:

Mass of solute = 40 g

Mass of solvent = 100 g

Mass of solution = Mass of (solute + solvent) = 40 g + 100 g = 140 g

Now, 140 g solution contain 40 g solute

then, 50 g solution will contain solute = (40 g/140 g)*100 = 14.29 g

More solute added = 5 g

Mass of solute in new solution = 14.29 + 5 = 19.29 g

Mass of new solution = 50 + 5 = 55 g

w/w% of new solution = (19.29 g/55 g)*100 = 35.07 %

Read More: Physical Change and Chemical Change

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