The weight percent is of caffiene is 7.98%.
There are several ways of expressing concentration in chemistry. One of the methods of expressing concentration is by the use of percentage.
In this case, we want to obtain the percent weight/weight concentration of caffeine in benzene.
From the question, we can see that;
Mass of solute = 6.5 g
Mass of solvent = 75 g
percent w/w = mass of solute/ mass of solute + mass of solvent × 100/1
percent weight of caffeine=
6.5/6.5 + 75 × 100/1 =7.98%
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