Keiko needs 100ml of a 5% acid solution for a science experiment. she has available a 1% solution and a 6% solution. how many milliliters of the 1% solution and how many milliliters of the 6% solution should she mix to make the 5% solution?

20 ml of the 1% solution and 80 ml of the 6% solution should she mix to make the 100 ml of 5% solution

The concentration of a substance can be expressed in several quantities such as moles, percent (%) weight / volume,), molarity, molality, parts per million (ppm) or mole fraction. Concentration shows the amount of solute in a unit of the amount of solvent.

Molarity (M)

Molarity shows the number of moles of solute in every 1 liter of solution.

Where

M = Molarity

n = Number of moles of solute

V = volume of the solution

For molarity a mixture can be formulated  :

Keiko needs 100 mL of a 5% acid solution

The available solutions are 1% and 6%

We can make a mathematical equation from the two statements above

The total volume of the 1% and 6% solutions is 100 ml

5% = 1% .V1 + 6% .V2 /( V1 + V2 )

5% = 1% .V1 + 6% .V2 / 100

5 = 1% .V1 + 6% .V2 or

500 = V1 + 6V2

Equations 1 and 2 we do elimination and substitution

500 = V1 + 6V2

100  = V1 + V2

----------------------- -

400 =  5V2

V2 = 80 ml

V1 = 20 ml

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Keywords: reaction coefficients, potassium carbonate, electrolytes