The diameter of a U.S. dime is 17.9 mm, and the diameter of a silver atom is 2.88 Å. How many silver atoms could be arranged side by side across the diameter of a dime? The diameter of a carbon atom is 1.54 Å.
(a) Express this diameter in picometers.
(b) How many carbon atoms could be aligned side by side across the width of a pencil line that is 0.20 mm wide?
Chem 112 9-7-16 What we have so far Reaction with reactant coefficients α and ß αA + ßB = γC + δD Overall rate expression: Rate = -ΔA/αΔt = -ΔB/ßΔt Rate laws relate exponents to orders of elementary reactions that are part of mechanisms o Not necessarily observable or able to be directly measured Rate = k[A]x[B]y Key: combine this knowledge to experimentally validate this proof Acquiring useful experimental data Method of initial rates o Why Reactants decrease over time, products increase A+B Products Vary [A]o and [B]o – keep one constant, vary the other, then vice versa Determine initial rates – measure the change in concentration change over short periods of time Observe the effects of the concentration changes on the reaction rate Analyze the data Integrated rate laws o A Products x Rate = -ΔA/αΔt = k[A] After some derivation: ln[A] – ln [A o = ln [A]/[A o = -kt, assuming a first order reaction. o Concentrations of compounds involved in chemical reactions change over time, as does the rate o Consider the rate as a function of concentration as Δt = 0