Physical and Chemical Changes Practice Test

Solid iodine, I$_2$(s), is placed in a sealed flask at room temperature. After several minutes, a purple vapor appears above the solid while some solid remains. Which statement best classifies the change?

Assume no other substances are present.

A sealed syringe contains a sample of nitrogen gas, N2(g). The plunger is pushed inward, decreasing the volume, and the gas pressure increases. No gas enters or leaves the syringe. Which statement best classifies the change that occurs to the nitrogen sample?