Final answer:
To create a 12% salt solution from 200 c.c of an 8% salt solution, 66.67 c.c of water must be evaporated. This is determined by calculating the initial amount of salt and setting up a ratio involving the final concentration after evaporation.
Step-by-step explanation:
To determine how many cubic centimeters (c.c) of water must be evaporated from 200 c.c of a 8% salt solution to form a 12% salt solution, we need to use the concept of percentage concentration in solutions. The amount of salt in the solution remains constant during the evaporation process; only the amount of water changes.
Let's denote the initial volume of water as V_initial and the final volume of water as V_final, where V_final = 200 c.c - x (the volume of water that needs to be evaporated).
The initial amount of salt in the 8% solution can be calculated as 0.08 * 200 c.c = 16 c.c. To find the final concentration of 12%, we set up the following ratio:
Final concentration = (Amount of salt) / (V_final)
0.12 = 16 c.c / (200 c.c - x)
By solving for x, we get:
0.12 * (200 c.c - x) = 16 c.c
24 c.c - 0.12x = 16 c.c
x = (24 c.c - 16 c.c) / 0.12
x = 66.67 c.c
Therefore, 66.67 c.c of water must be evaporated to obtain a 12% salt solution from 200 c.c of an 8% salt solution.