Question

1. which diagram best represents a homogeneous mixture of a compound and an element?
2. a new type of lip product is separated using chromatography on a glass plate with ethanol as the solvent. the chromatogram is shown on the right.

a. how many components made up the lip product?
b. what were the mobile and stationary phases in the experiment?
c. identify the most and least soluble colors that made up the lip product.
d. what kind of mixture does chromatography separate?

1. which is stronger: intermolecular forces or intramolecular forces?
2. which of the following substances cannot be broken down using chemical reactions?

a) c₃h₆
b) c₄h₈o
c) gold
d) water

1. which of the following represents a mixture?

a) aqueous nh₃
b) gaseous c₂h₆
c) liquid hg
d) solid i₂

Explanation:

4.

Step1: Recall mixture definitions

A homogeneous mixture has uniform composition. A compound has different - type atoms bonded, and an element has one - type atoms.

Step2: Analyze diagrams

Diagram e shows two different - looking particles (representing a compound and an element) evenly distributed, which is a homogeneous mixture.

5.

a.

Step1: Count spots on chromatogram

There are 4 spots (orange, yellow, pink, brown), so 4 components.

b.

Step1: Identify phases

The mobile phase is the moving part, which is ethanol. The stationary phase is the non - moving part, which is the glass plate.

c.

Step1: Understand solubility and chromatogram

The most soluble color travels the farthest. Orange travels the farthest, so it is the most soluble. Brown travels the least, so it is the least soluble.

d.

Step1: Recall chromatography principle

Chromatography separates homogeneous mixtures.

6.

Step1: Compare force strengths

Intramolecular forces (bonds within a molecule) are stronger than intermolecular forces (forces between molecules).

7.

Step1: Recall element and compound properties

Elements cannot be broken down by chemical reactions. Gold is an element, while \(C_3H_6\), \(C_4H_8O\), and water (\(H_2O\)) are compounds. So gold cannot be broken down by chemical reactions.

8.

Step1: Recall mixture and pure - substance definitions

A mixture contains two or more substances. Aqueous \(NH_3\) is a mixture of ammonia and water. Gaseous \(C_2H_6\), liquid \(Hg\), and solid \(I_2\) are pure substances.

Answer:

1. e
2. a. 4

b. Mobile phase: ethanol; Stationary phase: glass plate
c. Most soluble: orange; Least soluble: brown
d. Homogeneous mixture

1. Intramolecular forces
2. c. Gold
3. a. Aqueous \(NH_3\)