Question

name

1. which of the following are pure substances? which are mixtures?

a. ethanol b. vinegar c. motor oil d. helium

1. use the system types from table 2.3 to describe each of the following solutions.

a. ethanol in water b. sucrose in ethanol c. carbon in iron d. oxygen in water
section 2.3 elements and compounds

1. what elements make up chloroform, chemical formula chcl₃?
2. name the elements represented by the following chemical symbols.

a. pb b. k c. au d. fe

1. classify the following as elements, compounds, or mixtures.

a. salt b. water c. iron d. sterling silver

1. write the chemical symbol for each of the following elements.

a. chlorine b. sodium c. silver d. carbon
a liquid is allowed to evaporate and leaves no residue. can you determine
whether it was an element, a compound, or a mixture?
which of the following is not an element?
a. copper b. sulfur c. ammonia d. helium

Explanation:

Answer:

1. Pure substances: a. ethanol, d. helium; Mixtures: b. vinegar, c. motor oil
2. (Assuming Table 2.3 has solution types like aqueous, solid - solution, etc.): a. ethanol in water: aqueous solution (or liquid - liquid solution); b. sucrose in ethanol: solid - liquid solution; c. carbon in iron: solid - solution (alloy); d. oxygen in water: gas - liquid solution

SECTION 2.3

1. Carbon (C), Hydrogen (H), Chlorine (Cl)
2. a. Lead; b. Potassium; c. Gold; d. Iron
3. a. Compound; b. Compound; c. Element; d. Mixture (alloy)
4. a. Cl; b. Na; c. Ag; d. C

(For the liquid evaporation question): No, because both elements (like mercury) and compounds (like water) can evaporate leaving no residue, and mixtures could too if the solute evaporates.
(For "Which of the following is not an element?"): c. ammonia