Distinguishing Pure Substances from Mixtures

Distinguishing Pure Substances from Mixtures

• A pure substance has a constant composition, whereas a mixture has a variable composition.
• A pure substance can be an element (e.g., helium) or a compound (e.g., water, made up of hydrogen and oxygen atoms).
• A mixture is a combination of multiple pure substances, and its composition can vary (e.g., salt water, consisting of water and salt).

Characteristics of Pure Substances and Mixtures

• Pure substances:
  • Have a definite and constant composition.
  • Can be elements or compounds.
  • Examples: helium, water, hydrogen gas, salt (sodium chloride).
• Mixtures:
  • Have a variable composition.
  • Can be separated by physical processes (e.g., boiling, evaporation, filtration).
  • Examples: salt water, soda, milk, sea water, wood, soil, wine.

Separating Pure Substances and Mixtures

• Physical processes can separate the components of a mixture (e.g., boiling off water from salt water).
• Chemical processes can break down a pure substance into its component elements (e.g., electrolysis of water into hydrogen and oxygen).

Classifying Substances as Pure or Mixtures

• Carbon dioxide (CO2): pure substance (compound).
• Iron metal: pure substance (element).
• Brass: mixture (alloy of copper and zinc).
• Air: mixture (homogeneous mixture of gases).
• Sugar: pure substance (compound).
• Sugar water: mixture.
• 24-karat gold: pure substance (element).
• 14-karat gold: mixture (alloy of gold and other metals).
• Rubbing alcohol: mixture (isopropyl alcohol and water).
• Soda: mixture (water, sugar, caffeine, etc.).
• Milk: mixture (water, proteins, fat molecules, etc.).
• Silver metal: pure substance (element).
• Sterling silver: mixture (alloy of silver and copper).
• Sea water: mixture (salt water with other elements).
• Wood: mixture (carbohydrates, proteins, nucleic acids, etc.).
• Soil: mixture (sand, fertilizers, water, etc.).
• Wine: mixture (water and ethanol).

Distinguishing Pure Substances from Mixtures

• A pure substance has a constant composition, while a mixture has a variable composition.
• Pure substances can be elements or compounds, such as helium or water.

Characteristics of Pure Substances

• Have a definite and constant composition.
• Can be elements or compounds.
• Examples: helium, water, hydrogen gas, salt (sodium chloride).

Characteristics of Mixtures

• Have a variable composition.
• Can be separated by physical processes, such as boiling or filtration.
• Examples: salt water, soda, milk, sea water, wood, soil, wine.

Separating Pure Substances and Mixtures

• Physical processes can separate the components of a mixture, such as boiling off water from salt water.
• Chemical processes can break down a pure substance into its component elements, such as electrolysis of water into hydrogen and oxygen.

Classifying Substances

• Carbon dioxide (CO2) is a pure substance (compound).
• Iron metal is a pure substance (element).
• Brass is a mixture (alloy of copper and zinc).
• Air is a mixture (homogeneous mixture of gases).
• Sugar is a pure substance (compound).
• Sugar water is a mixture.
• 24-karat gold is a pure substance (element).
• 14-karat gold is a mixture (alloy of gold and other metals).
• Rubbing alcohol is a mixture (isopropyl alcohol and water).
• Soda is a mixture (water, sugar, caffeine, etc.).
• Milk is a mixture (water, proteins, fat molecules, etc.).
• Silver metal is a pure substance (element).
• Sterling silver is a mixture (alloy of silver and copper).
• Sea water is a mixture (salt water with other elements).
• Wood is a mixture (carbohydrates, proteins, nucleic acids, etc.).
• Soil is a mixture (sand, fertilizers, water, etc.).
• Wine is a mixture (water and ethanol).

Distinguishing Pure Substances from Mixtures

• A pure substance has a constant composition, while a mixture has a variable composition.
• Pure substances can be elements or compounds, such as helium or water.

Characteristics of Pure Substances

• Have a definite and constant composition.
• Can be elements or compounds.
• Examples: helium, water, hydrogen gas, salt (sodium chloride).

Characteristics of Mixtures

• Have a variable composition.
• Can be separated by physical processes, such as boiling or filtration.
• Examples: salt water, soda, milk, sea water, wood, soil, wine.

Separating Pure Substances and Mixtures

• Physical processes can separate the components of a mixture, such as boiling off water from salt water.
• Chemical processes can break down a pure substance into its component elements, such as electrolysis of water into hydrogen and oxygen.

Classifying Substances

• Carbon dioxide (CO2) is a pure substance (compound).
• Iron metal is a pure substance (element).
• Brass is a mixture (alloy of copper and zinc).
• Air is a mixture (homogeneous mixture of gases).
• Sugar is a pure substance (compound).
• Sugar water is a mixture.
• 24-karat gold is a pure substance (element).
• 14-karat gold is a mixture (alloy of gold and other metals).
• Rubbing alcohol is a mixture (isopropyl alcohol and water).
• Soda is a mixture (water, sugar, caffeine, etc.).
• Milk is a mixture (water, proteins, fat molecules, etc.).
• Silver metal is a pure substance (element).
• Sterling silver is a mixture (alloy of silver and copper).
• Sea water is a mixture (salt water with other elements).
• Wood is a mixture (carbohydrates, proteins, nucleic acids, etc.).
• Soil is a mixture (sand, fertilizers, water, etc.).
• Wine is a mixture (water and ethanol).

Distinguishing Pure Substances from Mixtures

• A pure substance has a constant composition, while a mixture has a variable composition.
• Pure substances can be elements or compounds, such as helium or water.

Characteristics of Pure Substances

• Have a definite and constant composition.
• Can be elements or compounds.
• Examples: helium, water, hydrogen gas, salt (sodium chloride).

Characteristics of Mixtures

• Have a variable composition.
• Can be separated by physical processes, such as boiling or filtration.
• Examples: salt water, soda, milk, sea water, wood, soil, wine.

Separating Pure Substances and Mixtures

• Physical processes can separate the components of a mixture, such as boiling off water from salt water.
• Chemical processes can break down a pure substance into its component elements, such as electrolysis of water into hydrogen and oxygen.

Classifying Substances

• Carbon dioxide (CO2) is a pure substance (compound).
• Iron metal is a pure substance (element).
• Brass is a mixture (alloy of copper and zinc).
• Air is a mixture (homogeneous mixture of gases).
• Sugar is a pure substance (compound).
• Sugar water is a mixture.
• 24-karat gold is a pure substance (element).
• 14-karat gold is a mixture (alloy of gold and other metals).
• Rubbing alcohol is a mixture (isopropyl alcohol and water).
• Soda is a mixture (water, sugar, caffeine, etc.).
• Milk is a mixture (water, proteins, fat molecules, etc.).
• Silver metal is a pure substance (element).
• Sterling silver is a mixture (alloy of silver and copper).
• Sea water is a mixture (salt water with other elements).
• Wood is a mixture (carbohydrates, proteins, nucleic acids, etc.).
• Soil is a mixture (sand, fertilizers, water, etc.).
• Wine is a mixture (water and ethanol).

Learn about the characteristics of pure substances and mixtures, including their compositions and properties.