Burning Solid Wastes

Rubber is essentially composed of hydrocarbon compounds with large molecular weights. A model of heat of combustion was created starting with methane and adding carbons. Paper is made of glucose polymers (cellulose). Another model of heat of combustion was made starting with glucose and adding more glucose compounds. Recursive formulas were generated for increasing each carbon chain. As more carbon is added to rubber, the amount of energy released per mole decreases. As more carbon is added to paper, the amount of energy per mole increases. Each approaches an asymptote. For hydrocarbons (rubber) this is about -35 kJ/g and for carbonhydrates (paper) it is about -27 kJ/g.

Thermodynamic Principles behind Refrigerators


Figure 1 shows the Clausius statement of the 2nd law of thermodynamics: heat cannot move from cold to hot unless work is done to the system. Figure 2 is a basic schematic of a typical refrigerator. 

Refrigerators work according to the Clausius statement of the second law of thermodynamic (Figure 1) that states that it is impossible for heat to move from a cold reservoir to a hot reservoir without work being done to the system.  A basic schematic of a typical refrigerator (Figure 2) illustrates this.From Valve 1 to Valve 2 (red; heat reservoir), the refrigerant is in a liquid form and releases the heat from the inside of the refrigerator to the outside (ie the kitchen). At valve 2, the expansion valve, the refrigerant is changed from a liquid to a vapor and pushed back inside the refrigerator. From valve 2 to the Compressor (blue, cold reservoir) the refrigerant, in vapor form, absorbs energy (ie. heat inside the refrigerator). At the compressor, work is done to the refrigerant to change it from a vapor to a liquid. The refrigerant is then pushed out of the refrigerator towards valve 1 and the process starts over.


Hello all! I’m Sarah Larson, a senior Chemistry Major with minors in Human Biology and Dance. I currently work on campus as a Student Ambassador and as a Lab Assistant. When I’m not busy with work and school (which is very rare) I spend most of my time dancing either at Ballroom Club or in the studio.