A chemist needs to prepare 500 ml of copper-sulfate solution with a 15% concentration. She wishes to use a high concentration solution (60%) and dilute it with a low concentration solution (5%) in order to do this. How much of the 60% solution should she use round to the nearest whole number? Do not use units

She should use 91 mL of the 60% solution (rounded to the nearest whole number).

Step-by-step explanation:

The first step to solve this question is to write the correct equations system. The two variables are :

: The amount of high concentration solution (60%) (in mL).

: The amount of low concentration solution (5%) (in mL).

The first equation for the mixing is :

(I)

Where , and represent the percentages for , and the final 500 mL of copper-sulfate solution respectively.

The second equation is :

(II)

The equation (II) represents that the sum from the volumes of high and low concentration solution must be 500 mL.

The final step is to solve this equation system :

From (II) we find that :

(III)

If we use (III) in (I) :

≅

She should use 91 mL of the 60% solution (rounded to the nearest whole number).

step-by-step explanation:

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have