CHEM 139: General Chemistry Prep
Active Learning Questions
Chapter 3: 4. Chapter 10: 3.
A white powder (consistent melting point of 635oC) is dissolved in water, resulting in a
clear liquid. A blue liquid (unmarked bottle, left on the lab bench by last quarter’s
class) is added, forming lots of heat, a yellow solid (with a consistent melting point of
880oC) and a colorless gas. Both liquids and both solids may be broken down into
something simpler by chemical means; the gas cannot. Classify each of the following as
a compound, element, or mixture--or state "not enough information to determine".
white powder
clear liquid
blue liquid
yellow solid
colorless gas
If “not enough information to determine,” what additional information do you need?
Is this a chemical change or a physical change?
Is this change endothermic or exothermic?