CH116lecture12P

CH116lecture12P - UMass Boston, Chem 116 CHEM 116 Rates of...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
UMass Boston, Chem 116 ©H.±Sev ian 1 CHEM 116 Rates of Reaction Lecture 12 Prof. Sevian FSG is cancelled today (Oct 14) in order to keep both FSG sections at the same pace (since there was no school yesterday) Today’s agenda z Graphing concentration data to determine reaction rates (ch. 14) z Initial rate of change vs. average rate of change z Concentration vs. time for one reactant that is measured z Concentration vs. time for other reactants and for products z Determining the order of a reaction from concentration vs. time data z Tables of initial reaction rates to determine the order of reaction for different species involved in a reaction
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
UMass Boston, Chem 116 ©H.±Sev ian 2 Kinetics: Key terms Rate law Concentration Catalyst Overall order of reaction Order with respect to a particular reactant Rate constant Half-life Collision model Activated complex/transition state Activation energy Arrhenius equation Reaction mechanism Elementary step in reaction mechanism Rate-determining step Molecularity of a step Equilibrium What makes kinetics difficult is that there are a lot of new ideas and new vocabulary all introduced at the same time. Becoming familiar with the vocabulary will help immensely. Kinetics z The study of how quickly (or slowly) reactions occur Using chemistry in the world: z How do you produce chemicals? z What kinds of chemical reactions are there? z What properties do materials have and why do they have those properties? z How much of a given chemical can you produce? How can you control it? z Stoichiometry z How fast do reactions occur? z How much energy does it take to make a reaction occur, or how much energy does a reaction give off? z How pure can you make the chemical? (Are there competing reactions?) z Scaling up reactions to useful proportions z How dangerous are specific chemicals? z LD50 of the desired products z Are there any byproducts or left over reactants? Are these dangerous?
Background image of page 2
UMass Boston, Chem 116 ©H.±Sev ian 3 What is rate of a reaction? z Comparison: What is rate of travel? How fast you travel. z Rate of a reaction is how fast the reaction happens z Measured mathematically as z What if you couldn’t measure reactant concentration but you could measure how much product is created? 1 2 1 2 travel of time traveled distance ) ( travel of rate t t d d Δ t Δ d speed = = = 1 2 1 2 ] A [ ] A [ ] A [ elapsed time ion concentrat chemical of change ) ( reaction of rate t t Δ t Δ rate = = = The class did four different experiments Control (same for everyone): 1 tablet Alka-Seltzer in 100 mL of room temperature water D) Twice as much water Groups 13, 14, 15 and 16 z Same control z Experiment: 1 tablet A-S in 200 mL (twice as much water as the control) C) Powdered tablet Groups 9, 10, 11 and 12 z Same control z Experiment: 1 crushed A-S tablet in same amount of room temp water B) Higher temperature Groups 5, 6, 7 and 8 z Same control z Experiment: 1 tablet A-S in 100 mL of very warm water A) 2 tablets instead of 1 Groups 1, 2, 3 and 4 z Same control z Experiment: 2 tablets instead of 1 tablet
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/02/2011 for the course PHYSICS 235 taught by Professor Staff during the Fall '08 term at Rutgers.

Page1 / 13

CH116lecture12P - UMass Boston, Chem 116 CHEM 116 Rates of...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online