Question

A famous chemical company in Oman hired you as a research chemist. On the very first day of your job, your senior

asked you to determine the density of a newly discovered unknown metal. In your lab, two liquids named X and Y are

available with densities of 3.0771 g/mL and 4.0017 g/mL respectively. In the process of finding density you made a

mixture of these liquids and drop a small object of that unknown metal, however, you notice that the object becomes

suspended in the liquid; that is, it neither sinks nor floats. If the mixture was made of 32.77 percent X and 67.23 percent

Y by volume, what is the density of the metal?

Select one:

a. 7.398 g/mL.

b. 2.413 g/mL

c. 2.360 g/mL

d. 3.699 g/mL

e. 3.539 g/mL

Answer 1

D. 3.699 g/mL

Step-by-step explanation:

Density of liquid X = 3.0771

Percentage composition of X in the mixture = 32.77% = 0.3277

Density of liquid Y = 4.0017

Percentage composition of Y in the mixture = 67.23% = 0.6723

Density of mixture of X and Y = (density of X × percentage composition of X) + (density of Y × percentage composition of Y)

Density of mixture of X and Y = (3.0771 × 0.3277) + (4.0017 × 0.6723)

Density of mixture of X and Y = 1.0084 + 2.6903

Density of mixture of X and Y = 3.6987 g/mL

When the metal of unknown density is dropped into a mixture of X and Y, it is suspended in the mixture. This is because it has a density equal to that of the mixture.

Therefore, the density of the unknown metal is 3.6987 g/mL which is approximately 3.699 g/mL to three decimal places.