1) identify each substance as either a pure substance or a mixture.
2) if it is a pure substance, state whether it is an element or a compound.
3) if it is a mixture, state whether it is homogeneous or heterogeneous.
remember:
pure substances have a fixed composition, and can be described with a single chemical formula.
mixtures have variable composition, and contain two or more substances physically combined.
material (formula or ingredients listed) | is it a pure substance or mixture? | for pure substances: is it an element or a compound? | for mixtures: is it homogeneous (uniform) or heterogeneous (non - uniform, colored, lumpy) |
lactose (c₁₂h₂₂o₁₁)
sugar water (c₁₂h₂₂o₁₁ + h₂o)
gold (au)
pure ethanol (c₂h₅oh)
dirt (sand + humus + clay)
sodium (na)
filtered air (h₂ + o₂ + n₂ + co₂)
oxygen (o₂)
fructose (c₆h₁₂o₆)
pure water (h₂o)
bottled water (h₂o + dissolved minerals)
iced tea (h₂o + dissolved tea)
chocolate chip ice cream (cream, chocolate, etc.)
steel (alloy) (fe + c + cr)
pure hydrochloric acid (hcl)
dinitrogen monoxide (n₂o)
sterling silver (alloy) (92.5% ag and 7.5% cu)
lotion (oil, water, wax, emulsifying agent)

Question

Accepted Answer

# Explanation:
## Step1: Recall definitions
Pure substances have fixed composition, mixtures have variable composition. Elements are made of one - type of atom, compounds are made of different types of atoms chemically combined. Homogeneous mixtures have uniform composition, heterogeneous mixtures have non - uniform composition.
## Step2: Analyze lactose ($C_{12}H_{22}O_{11}$)
It is a pure substance as it has a fixed chemical formula. It is a compound since it is made of carbon, hydrogen and oxygen atoms chemically bonded. It is not a mixture.
## Step3: Analyze sugar water ($C_{12}H_{22}O_{11}+H_2O$)
It is a mixture as it contains sugar and water. It is a homogeneous mixture as the sugar is dissolved uniformly in water.
## Step4: Analyze gold (Au)
It is a pure substance. It is an element as it is made of only gold atoms.
## Step5: Analyze pure ethanol ($C_2H_5OH$)
It is a pure substance with a fixed formula. It is a compound as it is composed of carbon, hydrogen and oxygen atoms.
## Step6: Analyze dirt (sand + humus+clay)
It is a mixture. It is a heterogeneous mixture as the components (sand, humus and clay) are not uniformly distributed.
## Step7: Analyze sodium (Na)
It is a pure substance. It is an element as it consists of only sodium atoms.
## Step8: Analyze filtered air ($H_2 + O_2+N_2 + CO_2$)
It is a mixture. It is a homogeneous mixture as the gases are uniformly mixed.
## Step9: Analyze oxygen ($O_2$)
It is a pure substance. It is an element as it is made of only oxygen atoms.
## Step10: Analyze fructose ($C_6H_{12}O_6$)
It is a pure substance. It is a compound as it is composed of carbon, hydrogen and oxygen atoms.
## Step11: Analyze pure water ($H_2O$)
It is a pure substance. It is a compound as it is made of hydrogen and oxygen atoms.
## Step12: Analyze bottled water ($H_2O$ + dissolved minerals)
It is a mixture. It is a homogeneous mixture as the minerals are dissolved in water.
## Step13: Analyze iced tea ($H_2O$ + dissolved tea)
It is a mixture. It is a homogeneous mixture as the tea is dissolved in water.
## Step14: Analyze chocolate chip ice - cream (Cream, chocolate, etc.)
It is a mixture. It is a heterogeneous mixture as the chocolate chips are not uniformly distributed in the cream.
## Step15: Analyze steel (alloy) ($Fe + C+Cr$)
It is a mixture. It is a homogeneous mixture as it is an alloy where the components are uniformly mixed at a microscopic level.
## Step16: Analyze pure hydrochloric acid (HCl)
It is a pure substance. It is a compound as it is made of hydrogen and chlorine atoms.
## Step17: Analyze dinitrogen monoxide ($N_2O$)
It is a pure substance. It is a compound as it is made of nitrogen and oxygen atoms.
## Step18: Analyze sterling silver (alloy) (92.5% Ag and 7.5% Cu)
It is a mixture. It is a homogeneous mixture as it is an alloy with a relatively uniform composition.
## Step19: Analyze lotion (oil, water, wax, emulsifying agent)
It is a mixture. It is a homogeneous mixture as the components are mixed to form a uniform product.

| Material (formula or ingredients listed) | Is it a pure substance or mixture? | For pure substances: Is it an element or a compound? | For mixtures: Is it homogeneous (solution) or heterogeneous (mechanical mixture, colloid, suspension)? |
|---|---|---|---|
| Lactose ($C_{12}H_{22}O_{11}$) | Pure substance | Compound | N/A |
| Sugar water ($C_{12}H_{22}O_{11}+H_2O$) | Mixture | N/A | Homogeneous |
| Gold (Au) | Pure substance | Element | N/A |
| Pure ethanol ($C_2H_5OH$) | Pure substance | Compound | N/A |
| Dirt (sand + humus + clay) | Mixture | N/A | Heterogeneous |
| Sodium (Na) | Pure substance | Element | N/A |
| Filtered air ($H_2 + O_2+N_2 + CO_2$) | Mixture | N/A | Homogeneous |
| Oxygen ($O_2$) | Pure substance | Element | N/A |
| Fructose ($C_6H_{12}O_6$) | Pure substance | Compound | N/A |
| Pure water ($H_2O$) | Pure substance | Compound | N/A |
| Bottled water ($H_2O$ + dissolved minerals) | Mixture | N/A | Homogeneous |
| Iced tea ($H_2O$ + dissolved tea) | Mixture | N/A | Homogeneous |
| Chocolate chip ice - cream (Cream, chocolate, etc.) | Mixture | N/A | Heterogeneous |
| Steel (alloy) ($Fe + C+Cr$) | Mixture | N/A | Homogeneous |
| Pure hydrochloric acid (HCl) | Pure substance | Compound | N/A |
| Dinitrogen monoxide ($N_2O$) | Pure substance | Compound | N/A |
| Sterling silver (alloy) (92.5% Ag and 7.5% Cu) | Mixture | N/A | Homogeneous |
| Lotion (oil, water, wax, emulsifying agent) | Mixture | N/A | Homogeneous |

Material (formula or ingredients listed)	Is it a pure substance or mixture?	For pure substances: Is it an element or a compound?	For mixtures: Is it homogeneous (solution) or heterogeneous (mechanical mixture, colloid, suspension)?
Sugar water ($C_{12}H_{22}O_{11}+H_2O$)	Mixture	N/A	Homogeneous
Gold (Au)	Pure substance	Element	N/A
Pure ethanol ($C_2H_5OH$)	Pure substance	Compound	N/A
Dirt (sand + humus + clay)	Mixture	N/A	Heterogeneous

QUESTION IMAGE

Question

Explanation:

Step1: Recall definitions

Step2: Analyze lactose ($C_{12}H_{22}O_{11}$)

Step3: Analyze sugar water ($C_{12}H_{22}O_{11}+H_2O$)

Step4: Analyze gold (Au)

Step5: Analyze pure ethanol ($C_2H_5OH$)

Step6: Analyze dirt (sand + humus+clay)

Step7: Analyze sodium (Na)

Step8: Analyze filtered air ($H_2 + O_2+N_2 + CO_2$)

Step9: Analyze oxygen ($O_2$)

Step10: Analyze fructose ($C_6H_{12}O_6$)

Step11: Analyze pure water ($H_2O$)

Step12: Analyze bottled water ($H_2O$ + dissolved minerals)

Step13: Analyze iced tea ($H_2O$ + dissolved tea)

Step14: Analyze chocolate chip ice - cream (Cream, chocolate, etc.)

Step15: Analyze steel (alloy) ($Fe + C+Cr$)

Step16: Analyze pure hydrochloric acid (HCl)

Step17: Analyze dinitrogen monoxide ($N_2O$)

Step18: Analyze sterling silver (alloy) (92.5% Ag and 7.5% Cu)

Step19: Analyze lotion (oil, water, wax, emulsifying agent)

Answer: