Simon has collected three samples from the coral reef where he observes marine life. He must determine whether each one is a pure substance or a mixture.
SAMPLE A : Clear liquid. Evaporates at 70C. Appearance does not change.
SAMPLE B : Clear, blue liquid. Boils at 90C leaving blue crystals behind. Appearance does not change.
SAMPLE C : Opaque, whitish liquid. Boils at 100*C leaving white crystals behind. Dust appears to settle at bottom.

Answer choices for each one are - homogeneous mixture, heterogeneous mixture, or pure substance

SAMPLE A - pure substance.
SAMPLE B - homogeneous mixture.
SAMPLE C - heterogeneous mixture.
Pure substance - constant composition and properties.
Homogeneous mixture - same uniform appearance and composition.
Heterogeneous mixture - not uniform in composition, two phases (liquid and dust).

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IlaMends IlaMends · Answer 2 · 2018-11-28T07:08:17+01:00

Answer: Sample A is a pure substance, Sample B is a homogeneous mixture and Sample C is a heterogeneous mixture.

Explanation:

Homogeneous mixture : In these mixture, all the component are uniformly distributed throughout the mixture.For example: sugar-water solution.

Heterogeneous mixture : In these mixture, all the component are not uniformly distributed throughout the mixture.For example: sand-water solution.

Pure substance : These are the substance made up only one type of atom or molecule.They have fixed value of boiling and melting points. For example: diamond, pure sugar etc.

Sample A is a clear liquid which evaporates at [tex]70^oC[/tex] with no change in appearance. Hence, pure substance.

Sample B is a clear blue liquid which boils at [tex]90^oC[/tex] and leaves blue crystals behind with change in appearance. Hence, homogeneous mixture

Sample C is a opaque, whitish liquid which boils at [tex]100^oC[/tex] and leaves white crystals behind with dust particles settled in the bottom. Hence, heterogeneous mixture.