In the following multiple-choice problems, circle the one answer which best completes the Sentence (i) (iii) (iv) (v) The glass transition temperature of polystyrene is about 110 °C. Relative to a sample at 120 °C, at room temperature polystyrene is: a. orders of magnitude more viscous b. slightly more viscous c. equally as viscous less viscous d. e. none of the above. The glass transition temperature of polystyrene is about 110 °C. Relative to a sample at 120 °C, a sample of polystyrene at 130 °C is: a orders of magnitude more viscous b. slightly more viscous c. equally as viscous d. less viscous e. none of the above. Suppose a tensile test is performed on two identical materials except that one has a deep scratch on its surface whereas the other is perfectly smooth. Relative to the smooth specimen, the test will find that the scratched specimen has a lower. a. elasticity b. yield stress c. tensile stress d. elongation to failure e. none of the above. Thermoplastic polymers such as…

Identify reagents A and B in the following reaction scheme. This synthetic sequence was used to prepare the C16 juvenile hormone (Figure 20.6). он OH (excess) (excess) several steps several steps čo,CH3 OH OH C18 juvenile hormone

The Occupational Safety and Health Administration has established a Permissible Exposure Limit of 200 parts per million (ppm) for toluene. As an industrial hygienist, you are doing personal sampling on a worker who is in charge of a production process that uses toluene. The upcoming exposures can be measured: During one hour, 500 ppm 100 ppm for four hours and 225 ppm for three What is the TWA as calculated? What advice would you provide plant management regarding toluene exposure and PEL adherence?