Energy and Polymers Ch 16
molecules
polymers Monomer: single molecule Polymers: chain of monomers Ex: monomer: glucose- simple sugar for immediate energy polymer: glycogen- complex carb for stored energy
Energy and polymers Energy is stored in the bonds of molecules. ex: fat molecules are complex to store energy, when the energy is needed, it is broken down for release the energy
Chemical reactions either require or release energy! Breaking bonds releases energy, forming bonds stores energy, but both need energy to happen
Activation energy: energy needed to start a reaction Catalyst: lower amount of energy required for a reaction to take place
overall absorption of energy: (feels cold) Endothermic rxn: overall absorption of energy: (feels cold) Ex: Exothermic rxn: Overall release of energy (feels hot) D[Br2] a DAbsorption
Entropy: measure of the disorder of a system Can measure with energy, nature tends toward disorder (2nd law of thermodynamics) Ex: glucose, glycogen
Takes energy to organize, lose energy makes less organized Low entropy High entropy
Warm up How are entropy and energy related? What is happening to the long chain polymer below? Is energy and entropy increasing or decreasing?
Today Add application to you slides on polymer and entropy presentation Edit and finalize slides and email to Mrs. D davisson_sarah@lacoe.edu Work on science fair project: pg 3 of packet
Electromagnetic Waves Review of Light Electromagnetic Waves Electromagnetic Spectrum is a continuous range of waves extending from the longest (Radio) and going to the shortest (Gamma).
Light Any material that allows light to pass through in straight lines is said to be transparent. EX: Glass Water Any material that absorbs light w/o reemission is said to be opaque. EX: Wood Stone
Light Light is a transverse wave. White light is Non-polarized. POLARIZATION Light is a transverse wave. White light is Non-polarized. When passed through a filter (Polarizer) only light that is moving same as the filter opening will make it through. Fig. 27.18
Polarized light
Polarization Photography Reduce Sun Glare Reduce Reflections Darkens Sky Increase Color Saturation Reduce Haze
Polarization Photography Without Polarizer With Polarizer Provides better Color Saturation Darkens the sky
Polarization Photography Without Polarizer With Polarizer
Polarization Photography : Scattering Haze De-hazed
Polarized Sunglasses Reduce glare off the roads while driving
Crossed Polarizers
Birefrengence Interference pattern due to different refractive indices
birefringence
Read and take notes -in notes section of notebook Ch 16.1 pg 531 to 538 Make a vocab list for yourself in your notes
Change room to group set up Add to notes: Enthalpy: amount of energy absorbed by a system during a process (ΔH = change in enthalpy)
Enthalpy: amount of energy absorbed by a system during a process (ΔH = change in enthalpy)
Water producing cars?
ΔHsoln = J/g (Joules/gram solute) ΔHsoln or heat of solution: enthalpy change associated with the process of a solute (solid) dissolving in a solvent (liquid) ΔHsoln = J/g (Joules/gram solute) amount of heat change (q), can be calculated using a calorimeter and the equation: q= m × s × ΔT Joules= unit of energy s=4.18J/g °C m = total mass of the solution (solute plus solvent), S = specific heat constant of the solution ΔT = observed temperature change ex: 5.0g solute dissolved in 10g water with a temp change of 12.0 °C. What is the heat of solution?
ΔHsoln = J/g (Joules/gram solute) = 572J/ 5.0g = 150J/g ex: 5.0g solute dissolved in 10g water with a temp change of 12.0 °C. What is the heat of solution? q= m × s × ΔT m = total mass of the solution (solute plus solvent), S = specific heat constant of the solution ΔT = observed temperature change m=5g + 10g = 15.0g q= 15.0g x 4.18J/g°C x 12.0C = 572J ΔHsoln = J/g (Joules/gram solute) = 572J/ 5.0g = 150J/g
Using a calorimeter to calculate energy change
Today Read lab and start lab report: design procedures and data table Complete Enthalpy lab HW: enthalpy lab analysis questions: worksheet