Determine whether each of the following represents a physical property or a chemical property. Vinegar has a pungent odor. Carbon cannot be decomposed. Sulfur is a bright yellow. Sodium chloride is a crystalline solid. Water does not burn. Ten mL of mercury is a liquid at 25°C. Oxygen is not combustible. Aluminum combines with oxygen to form a protective oxide coating. The density of water at 4°C is 1.000 g/mL. Hydrogen gas is very flammable. U4-4

Determine whether each of the following represents a physical property or a chemical property. Physical (intensive) Chemical Physical (extensive - 10 mL; intensive liquid at 25°C) U4-4

State whether each of the following represents a chemical change or merely a physical change. The lasagna was baked in the oven for 1 hour. In the lab, a student mixes 2 mL of ammonium chloride with 2 mL of hydrochloric acid in a test tube. He notices that the test tube become cooler. When potassium iodide and lead(II) nitrate are mixed together, a yellow solid forms. A few grams of table salt are placed in a small beaker of deionized water; the salt crystals “disappear” and the liquid in the beaker remain clear and colorless. A copper statue, over time, turns green. In the lab, a student cuts magnesium ribbon into 1-cm strips. 25 grams of ice melted at room temperature. U4-4

U4-4 Chemical (cooking always indicates chemical) State whether each of the following represents a chemical change or merely a physical change. Chemical (cooking always indicates chemical) Chemical (indicator: change in energy) Chemical (indicators: change in color and formation of precipitate) Physical (forms mixture not a new substance) Chemical (indicator: change in color) Physical (changes size not composition) Physical (phase changes are always physical) U4-4