Energy Bar Graphs - Riverside High School

Energy Bar Graphs - Riverside High School

Energy Bar Charts How to represent the role of energy in physical change Modeling Chemistry 2007 Constructing an Energy Bar Chart Consider this example A cup of hot coffee cools as it sits on the table.

1. Determine what is in the system cup coffee Everything else makes up the surroundings Decide whether Ech is involved In this case, you start with coffee and end with coffee; particles are not rearranged

to form new substances So, ignore Ech for now. Assign values to Eph Due to interactions between particles, the energy stored due to the arrangement of particles is ranked:

solids < liquids < gases We choose to represent these phases by using: Solids = 1 bar Liquids = 2 bars Gases = 4 bars Assign values to Eph

Use two Eph bars before and after cup coffee Choose bars for Eth depending on temperature Use 4 bars for hot coffee and 2 bars for room temp coffee

cup coffee Other values might also work; try to be consistent in your representations Now show energy transfer

Final situation has 2 less bars of E than initial; 2 bars had to leave the system Now, consider phase change A tray of ice cubes (-8 C) is placed on the counter and becomes water at room temperature What do we know about the situation?

The system is the tray of ice cubes. The solid water turns to liquid water - no change in Ech The Eph increases (solidliquid) The Eth increases (temp rises)

Now represent these changes in bar graph. Initial & Final States Choice of bars for Eth arbitrary, but consistent.

We generally use 2 bars for room temp and one bar for cold liquid-8C should be < 1 bar. Account for Energy Energy must flow into system via heating

Recently Viewed Presentations

  • Cell Structure &amp; Function - Lake Stevens School District

    Cell Structure & Function - Lake Stevens School District

    Arial Calibri Default Design Cell Structure & Function Definition of Cell Examples of Cells "Typical" Animal Cell "Typical" Plant Cell Cell Parts 1. Nucleus 3. Chromatin 4. Nucleolus 5.Nuclear Pores 6.Cytoplasm Endoplasmic Reticulum 9.Ribosomes 10.Mitochondria 11.Golgi Bodies 12.Lysosome 13. Vacuoles...
  • Duty to Love - Rom. 12:9-13

    Duty to Love - Rom. 12:9-13

    Modified by Jim McGowan. Israel. How futile for conservative scholars to ignore that fact and to seek to find literal fulfillment of those prophecies in history or in the church, when those predictions refer to events yet future and have...
  • Lecture 13 Parse Tree

    Lecture 13 Parse Tree

    Lecture 13 Parsing and Ambiguity Lecture 13 Parsing and Ambiguity Given a string x and a CFG G = (V, Σ, R, S), determine whether x L(G) and if x L(G), find a derivation S * x.
  • Latent Tree ModelsPart IV: Applications

    Latent Tree ModelsPart IV: Applications

    On interesting method uses latent tree models as a secondary representation. It has two phases, an offline phase and an online phase. In the offline phase, it samples a data set from the original network and learns a latent tree...
  • How to Maintain Competency for ECMO Specialists in a Low ...

    How to Maintain Competency for ECMO Specialists in a Low ...

    Wet Drills. Initials. Dates. a) Biannually completed a timed "Wet Drill Emergency Skills" check off under supervision of an ECMO Program Primer (Spring) b) Biannually completed a timed "Wet Drill Emergency" Skills checkoff under the supervision of an ECMO Program...
  • The Microscope

    The Microscope

    coarse adjustment, so the specimen is as close to the lenses as possible without touching it. Look through the eyepiece lens and . focus . until the image is sharp using the . fine adjustment. Switch to the next power...
  • Insert Your Title - PaintSquare

    Insert Your Title - PaintSquare

    Acrylic Polymer Technology. Acrylics are based on esters of acrylic and methacrylic acid, but can also include other non-acrylic monomers such as styrene and vinyl acetate. Solventborne and waterborne acrylic polymers are available. First uses date to the late 1920's,...
  • Vocab Chapt. 1 LoF  Efflorescence: (noun)  Blooming of

    Vocab Chapt. 1 LoF Efflorescence: (noun) Blooming of

    Vocab. Hiatus: (noun) . a gap or interruption in continuity; a break or pause. Synonym?? Antonym??