Q. 3.4 - An Introduction to General, Organic, and Biological Chemistry

Question

Classify each of the following as a pure substance or a mixture:

a. a soft drink

b. propane $\left({\mathrm{C}}_3{\mathrm{H}}_8\right)$

c. a cheese sandwich

d. an iron ($Fe$) nail

e. salt substitute $\left(KCI\right)$

Step-by-Step Solution

Answer

a. Soft drink is a mixture

b. propane is a  substance

c. cheese  sandwich is a mixture

d. iron is a substance

e. salt substitute is a substance

Step 1: Given Information (a)

(a) A pure substance or a mixture of soft drink

Step 2: Explanation (a)

(a) A potable may be a mixture of water, sugar, color, flavor, soda, and artificial sweetener. This mixture is physically mixed but not chemically combined.
Therefore, a potable may be a mixture 

Step 3: Given Information (b)

(b) A pure substance or a mixture of  Propane

Step 4: Explanation (b)

(b) Propane $\left({\mathrm{C}}_3{\mathrm{H}}_8\right)$ could be a gas. it's derived from gas and petroleum. It can't be separated by any physical or activity.
Therefore, propane $\left({\mathrm{C}}_3{\mathrm{H}}_8\right)$ may be a pure substance.

Step 5: Given Information (c)

(c) A pure substance or a mixture of cheese sandwich.

Step 6: Explanation (c)

(c) A cheese sandwich is formed of bread and cheese. it should also include vegetables or meat and condiments. This mixture is physically mixed but not chemically combined.
Therefore, a cheese sandwich could be a mixture.  

Step 7: Given Information (d)

(d) A pure substance or a mixture of Iron.

Step 8: Explanation (d)

(d) Iron ($Fe$) is a part. it's composed of just one form of material. It can't be separated by any physical or natural action.
Therefore, an iron ($Fe$) nail may be a pure substance

Step 9: Given Information (e)

(e) A pure substance or a mixture of Salt substitute

Step 10: Explanation (e)

(e) Salt substitute $\left(KCI\right)$ means K-Dur $20$ . it's a compound. it's a composed of atoms of two or more elements. they're chemically combined within the same proportion. Therefore, salt substitute $\left(KCI\right)$   could be a pure substance.