Question

Difficulty: HardProperties of Matter

Match each physical or chemical process involving matter on the left with its correct scientific classification and underlying property on the right.

  • Sublimation of solid carbon dioxide (dry ice) at room temperatureEndothermic physical phase transition from solid to gas without forming new chemical bonds
  • Rise of liquid mercury inside a calibrated thermometer columnPhysical change based on the intensive property of thermal expansion without changing chemical composition
  • Gradual formation of a green patina on an outdoor copper surfaceChemical change involving atmospheric oxidation and the synthesis of new chemical compounds
  • Fractional distillation separating hydrocarbon components from crude oilPhysical separation process that utilizes differences in boiling points, an intensive physical property

Answer

The sublimation of dry ice matches the endothermic phase transition; mercury rising in a thermometer matches the physical change driven by thermal expansion; patina formation on copper matches the chemical oxidation change; and fractional distillation matches the physical separation exploiting boiling points.
Each item is matched by determining whether the process alters the chemical identity of the substance or merely its physical state and dimensions. Sublimation of carbon dioxide is a physical phase change; mercury expansion is physical thermal expansion; fractional distillation uses boiling point differences for physical separation; and patina on copper is chemical oxidation forming new chemical compounds.

Step-by-Step Solution

1
Analyze the sublimation of dry ice
Dry ice transitions from solid to gaseous carbon dioxide (CO2CO_2) without altering molecular composition, which represents a direct solid-to-gas physical phase change.
Phase transitions alter physical state through energy transfer (latent heat) without forming or breaking intramolecular chemical bonds.
2
Analyze the rise of liquid mercury in a thermometer
Liquid mercury expands predictably when heated, which is an application of thermal expansion (an intensive physical property).
Volume changes resulting from temperature fluctuations do not transform the elemental identity of mercury.
3
Analyze the development of copper patina
Copper metal reacts chemically with atmospheric gases (oxygen, water vapor, sulfur/carbon compounds) to synthesize copper carbonate or copper sulfate.
The production of new substances with distinct chemical formulas and properties constitutes a chemical change.
4
Analyze fractional distillation of crude oil
Crude oil is heated so that hydrocarbons vaporize and condense at their respective characteristic boiling point thresholds.
Boiling point is an intensive physical property used to separate physical mixtures without chemical transformation.

Key Concept

Distinguishing between physical properties and changes (phase transitions, thermal expansion, separation by boiling point) versus chemical changes (oxidation and compound formation).
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