Question

8. Design an experiment that would test the effect of removing heat energy from a slightly stretched rubber band. You will not perform this experiment, but the materials you intend to use should be ones you would normally find at a college. Include in your design:

• A list of the materials required.
• A brief description of the procedure you would use (a diagram might be useful).
• The observations you would expect to see. Explain these observations in terms of both free energy changes and equilibrium.

Answer 1

MATERIAL Two the litre soda bottle Permanent Marker. Scissor Peneil thin rubber band Hot tap water hot water the cubes. pan / bowl. -dou Lold water. Tape 20-25 quarters PROCEDURE y cut the top part of soda bottle, turnine ento cylinder shape. & use tape to protect the catted part: make small holes in the opposite sides Just two inch below the lop edge. & pone peneil from one to another whole Tape together around 20 quaters with a paper clip as hook to streek out rubber band While hanging & place the bottle inside a bowl or pan. for clean experiment & fill it with hot water upto the pencil level. - use a permanent marker to draw a line on bottle that is lives with rubber band

- Now add ice gently and cubes. to bottle & still stiri gently add up to the temperature decreases abruptly a look at the side of the bottle again, so your eyes lenet with bottom of rubber band & mark the bottom of the rubber band OBSERVATION length of rubber band in hot water < length of wale rubber band in cold water LHOR LLOR this unusual behaviour is seen because of the unusital polymer structure. since on cooling spontaneity /entropy decreases. Дs 2 – и . 4H 2 – ие At 4G 24H - TAS To make 4G negative & reaction spontaneous AH has to be quantitatively high so in cold water the rubber band get stretche red. To return back to its equilibrium et need a fore fakx. where a string constant. x2 stretched length this can be gained by adding again temperature / heat energy.
On decreasing temperature or on removal of heat energy rubber band gets elongated . Which is contrary to what usually happens that is on addition of temperature material get elongated . This unusual behavior is due to unusual polymer structure of rubber