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

When the volume and number of particles of a gas are constant which of the following is also constant

Follow the steps provided in the simulation to add water to the graduated cylinder, select one of the three samples (copper, silver, or gold), set its mass to the values given in the statements below, and calculate its density. here is a summary of the steps required: add water by clicking and holding prepare a known volume of water button. until the desired volume of water has been added. if more than the desired volume is added, click the reset button. button and redo the procedure. a single click will add about 21.0 ml of water. to set the mass, click and hold weigh out metal button. until the desired amount of metal is added to the weighing pan. once the desired mass of the metal is added, release the button. transfer the metal to water and then click on calculate density button. to see how the density is calculated using water displacement to measure the volume of the solid. to save time you can approximate the initial volume of water to â±1 ml and the initial mass of the solid to â±1 g. for example, if you are asked to add 23 ml of water, add between 22 ml and 24 ml. which metals in each of the following sets will have equal density? check all that apply.

Which of these would be caused by a chemical change? a) the formation of lava. b) sedimantary rock layering over time. c) metamorphic rock forming from igneous. d) metamorphic rock eroding to form sedimentary rock.