Question

1. an example of a heterogenous mixture is

a. brass
b. tap water
c. sweet tea
d. lemonade with pulp
e. vinegar

1. which of the following is false about composition of matter?

a. different compounds can have the same elements in different ratios.
b. the % mass composition of a compound will be increase when you have more total mass of the compound.
c. the laws of proportions define composition quanttiatively.
d. h₂o and h₂o₂ obey the law of multiple proportions because their ratios of h:o are different.

1. sugar dissolved in hot coffee can be defined as a: (select all which are true)

a. pure substance
b. chromatograph
c. homogenous mixture
d. heterogenous mixture
e. solution

1. which of the following is a compound?

a. tap water
b. purified water
c. saltwater
d. none of these are compounds.
e. all of these are compounds.

1. which of the following is false about matter?

a. elements cannot be chemically or physically separated.
b. pure substances cannot be chemically or physically separated.
c. mixtures are physical combinations of pure substances.
d. compounds are chemical combinations of elements.
e. compounds in mixtures retain their own physical properties.

1. select all matter below that meets the defintion of is a pure substance:

a. oxygen
b. vinegar
c. air
d. purified water
e. carbon dioxide
matching
match the separation method best suited for the described process of a mixture:
a. filtration
b. crystalization
c. distillation
d. chromatography

1. identify toxins in a sample of blood
2. obtain solid sea salt from ocean water
3. remove coffee grounds from overnight cold brew
4. refine crude oil to obtain gasoline

Explanation:

Step1: Define heterogeneous mixture

A heterogeneous mixture has visibly different parts or phases. Lemonade with pulp has solid pulp particles in liquid lemonade, so it is a heterogeneous mixture. Brass is an alloy (homogeneous), tap - water has dissolved substances uniformly (homogeneous), sweet tea is a solution (homogeneous), vinegar is a solution (homogeneous).

Step2: Analyze statements about matter composition

The mass - percentage composition of a compound is fixed by its chemical formula and does not change with the amount of the compound. For example, water ($H_2O$) always has 11.19% hydrogen and 88.81% oxygen by mass regardless of the volume or mass of water.

Step3: Classify sugar - dissolved in coffee

Sugar dissolved in hot coffee is a homogeneous mixture (solution) because the sugar molecules are uniformly distributed in the coffee. It is not a pure substance as it is a combination of sugar and coffee substances. Chromatograph is a technique, not a classification of the mixture.

Step4: Identify compounds

Purified water ($H_2O$) is a compound as it is made up of hydrogen and oxygen atoms chemically bonded. Tap water is a mixture, salt - water is a mixture.

Step5: Evaluate statements about matter

Elements cannot be chemically or physically separated into simpler substances. Pure substances can be elements or compounds. Compounds in mixtures retain their physical properties. Mixtures are physical combinations of pure substances. The false statement is that pure substances cannot be chemically or physically separated (compounds can be chemically separated).

Step6: Define pure substances

Oxygen ($O_2$), purified water ($H_2O$), and carbon - dioxide ($CO_2$) are pure substances. Oxygen is an element, purified water and carbon - dioxide are compounds. Vinegar is a mixture, air is a mixture.

Step7: Match separation methods

Chromatography is used to identify toxins in a sample of blood as it can separate and identify different components based on their affinities. Crystallization is used to obtain solid sea salt from ocean water as the salt can be made to crystallize out. Filtration is used to remove coffee grounds from overnight cold - brew as it separates solids from liquids. Distillation is used to refine crude oil to obtain gasoline as it separates components based on their boiling points.

Answer:

1. d. lemonade with pulp
2. b. The % mass composition of a compound will be increase when you have more total mass of the compound.
3. c. homogenous mixture, e. solution
4. b. purified water
5. b. Pure substances cannot be chemically or physically separated
6. a. oxygen, d. purified water, e. carbon dioxide
7. d. chromatography
8. b. crystalization
9. a. filtration
10. c. distillation