Answer:
The volume or amount of pure cordial to be added to the solution to make the strength 20% is 125 ml
Step-by-step explanation:
The given parameters, are;
The volume of cordial in the jug = 1 litre
The percentage strength of the cordial = 10%
The proportion of the cordial that contains pure cordial = 0.1
Therefore, the volume of pure cordial in the jug = 0.1 × 1 = 0.1 × 1000 ml = 100 ml
The volume of the solvent = The volume of the solution - The initial volume of pure cordial
∴ The volume of the solvent = 1000 ml - 100 ml = 900 ml
To increase the concentration of the cordial to 20% is given by the relation;
x/(x+900) = 0.2
Where;
x = The total volume of the pure cordial to be added to the pure solvent
Solving, gives;
x = 0.2×(x+900) = 0.2·x + 180
x -0.2·x = 180
0.8·x = 180
x = 180/0.8 = 225 ml
The total volume of the pure cordial to be added to the pure solvent = x = 225 ml
Therefore, the volume of pure cordial to be added to the initial volume of pure cordial in the solution, which is 100 ml, is therefore given as follows;
The volume or amount of pure cordial to be added = 225 ml - 100 ml = 125 ml.
The volume or amount of pure cordial to be added = 125 ml