Rubbing alcohol is an aqueous solution containing 70% alcohol by volume. How would you prepare 250ml rubbing alcohol from pure alcohol ?
Answers
Creating dilutions reduces the concentration of one liquid with the addition of another. In order to create 70 percent isopropyl alcohol, a solution of isopropyl alcohol with a concentration greater than 70 percent must be diluted by a calculated amount of water. The formula for this calculation is C1_V1=C2_V2, where C1 and V1 is the starting concentration and volume of the solution and C2 and V2 is the final concentration and volume of the dilution. For the purpose of this example, the initial solution is 100 percent isopropyl alcohol, creating a final volume of 500 mL of 70 percent isopropyl alcohol.
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Identify the initial concentration of the 100 percent isopropyl alcohol, which is the C1 variable in the equation. The variable C1=100.
Determine the desired concentration and volume of the final solution to obtain C2 and V2. In this instance the final concentration C2 is 70 percent and final volume V2 500 mL; So C2=70 and V2=500.
Solve the equation C1_V1=C2_V2 for the unknown variable of V2. Substitute known variables: 100_V1=70_500, V1=35000/100, V1= 350. It is determined that 350 mL of 100 percent alcohol is needed for the preparation.
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Answer:I think combined x2 the grams for solution and the 70% is will be an highest volume and it will become an 90%..then the 250ml combined by the 70% of solution..
Explanation: