q9bsol - of disorder. Hence, the knee in the V versus T...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
3.091 Fall Term 2004 Homework Quiz #9B solution outline (a) A melt of borate glass, g 1 , cooled at rate, r 1 , has glass transition temperature, T g 1 . If a second specimen of molten g 1 is cooled at a new rate, r 2 , such that r 2 < r 1 , how does the glass transition temperature, T g 2 , compare to T g 1 ? Explain with reference to atomic structure. All other things being equal, i.e., melt composition, the higher the cooling rate, the higher the glass transition temperature. Therefore, T g 2 < T g 1 , since r 2 < r 1 . At the molecular level, the higher cooling rate allows less time for the liquid to rearrange itself in search of the crystal structure before onset of solidification. This has the effect of quenching in a greater amount
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: of disorder. Hence, the knee in the V versus T curve will lie at a higher temperature for a melt cooled at the higher rate (b) The fictitious compound, arrhenium fluoride (AhF), reacts with itself to form a dimer with the formula Ah 2 F 2 . The reaction is second order in AhF. The value of the rate constant is 7.7 10 3 M 1 s 1 . What is the initial rate of reaction in a reactor filled with AhF to a concentration of 3.091 M? Express your answer in M s 1 . 1 1 dc = kc 2 = 7.7 10 3 M s (3.091 M ) 2 = 7.36 M s 1 dt...
View Full Document

This note was uploaded on 11/02/2009 for the course CHEMISTRY 3.091 taught by Professor Donsadoway during the Fall '04 term at MIT.

Ask a homework question - tutors are online