The quenching of tryptophan fluorescence by dissolved o2 gas was monitored by measuring emission lifetimes at 348 nm in aqueous solution. (a) determine the quenching rate constant (ko) from the following data by substituting (τ/t) in place of (θ.0/9) in the stern-volmer equation and then dividing both sides by to. use excel or another plotting tool to fit the data to the resulting form of the stern-volmer equation and show your plot in the space below, with both the linear fit and the r2 value shown on the plot. (hint: watch your units when interpreting you plotline fit! ) [02]/mol/l t /109 s 0.000 0.023 0.055 0.080 0.108 2.60 50 0.92 0.7 0.57

Does the energy in a solid increase or decrease when changing to a liquid?

Which of these best describes an ionic bond?

Answer asap need to be answered by wednesday morning explain how a buffer works, using an ethanoic acid / sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.