Experiment #1 Post-Lab

Candle Burning Class observations for Part B and C Class observations for Part B and C Sample observations: Sample observations: 1. Colors of: flame, wick, “wax” 2. “wax” is an interpretation! 3. other senses? (smell, touch, etc) 4. Heat rises? (observation or interpretation?) 5. Qualitative vs. Quantitative “Candle is bright” “Candle is bright in a normally lit room” “Candle is as bright as a cm 2 of Fe raised to a temperature of 700 o C.

How does a candle work? -Hints: *Consider the shape that was “burned” into the note card. What does this tell you about the wick’s role? *Consider the similarities and differences between the three items that hold a flame up front (candle, tiki torch, bunsen burner) *Consider the 3 phases that are present when the candle is burning *What does “wick” actually mean? What does a wick do for a candle? *Why did the flame seem to “jump” in Part C #1? *Why was the flame extinguished in Part C #8?

How a candle works The wick is “lit” by a heat source The wick is “lit” by a heat source This begins to melt the solid paraffin wax into liquid wax. This begins to melt the solid paraffin wax into liquid wax. The wick will then “wick” or draw the liquid wax toward the flame where the reaction is taking place The wick will then “wick” or draw the liquid wax toward the flame where the reaction is taking place The liquid wax becomes a gas and it is this gas that is undergoing the combustion reaction The liquid wax becomes a gas and it is this gas that is undergoing the combustion reaction In the tiki torch, the fuel is already a liquid, and the wick draws the liquid toward the reaction site (flame) In the tiki torch, the fuel is already a liquid, and the wick draws the liquid toward the reaction site (flame) In the Bunsen burner, the fuel is already a gas so the reaction happens immediately In the Bunsen burner, the fuel is already a gas so the reaction happens immediately The wick is actually not the fuel like many people believe… it’s actually the wax of the candle! The wick is actually not the fuel like many people believe… it’s actually the wax of the candle! The wick is actually cooled by the vaporizing wax (like our sweat cools us) The wick is actually cooled by the vaporizing wax (like our sweat cools us) The wick becomes black and brittle because when the flame is extinguished, the liquid wax that is saturating it cools and becomes a solid again The wick becomes black and brittle because when the flame is extinguished, the liquid wax that is saturating it cools and becomes a solid again