Data Collection Mass of the original sample of mixture (g) 1.558
Mass of recovered naphthalene (g) 0.483
Mass of recovered 3-nitroaniline (g) 0.499
Mass of recovered benzoic acid (g) 0.467
Calculations:
a. % by mass of naphthalene in original sample.
b. % by mass of 3-nitroaniline in original sample.
c. % by mass of benzoic acid in original sample.
d. total percent recovered.

For a): The mass percent of naphthalene in the original sample is 31.00 %.

For b): The mass percent of 3-nitroaniline in the original sample is 32.03 %.

For c): The mass percent of benzoic acid in the original sample is 29.97 %.

For d): The total percent recovered is 93.00 %.

Explanation:

Percentage by mass is defined as the ratio of the mass of a substance to the mass of the solution multiplied by 100. The formula used for this is:  

              ......(1)

a):

Mass of naphthalene = 0.483 g

Mass of the sample = 1.558 g

Plugging values in equation 1:

b):

Mass of 3-nitroaniline = 0.499 g

Mass of the sample = 1.558 g

Plugging values in equation 1:

c):

Mass of benzoic acid = 0.467 g

Mass of the sample = 1.558 g

Plugging values in equation 1:

d):

Total mass recovered = [0.483 + 0.499 + 0.467] = 1.449 g

Mass of the sample = 1.558 g

Plugging values in equation 1:

the answer is d. 74.02