You need a 50% alcohol solution. On hand, you have a 250 mL of a 15% alcohol mixture. You also have 75% alcohol mixture. How much of the 75% mixture will you need to add to obtain the desired solution

350 mL

Explanation:

We need a 50% alcohol solution and we have 2 mixtures. One is 75% alcohol while the other is 15% alcohol.

Quantity of 15% alcohol is 250 mL.

Let quantity of 75% alcohol mixture be x.

Thus, we will produce;

0.5(x + 250)

Now, the reaction that will procuce this quantity is;

Sum of actual quantity of alcohol in each solution which is;

0.75x + 0.15(250)

Thus, equating both we have;

0.75x + 0.15(250) = 0.5(x + 250)

0.75x + 37.5 = 0.5x + 125

0.75x - 0.5x = 125 - 37.5

0.25x = 87.5

x = 87.5/0.25

x = 350 mL

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.

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