| This thesis describes two different sets of experiments. The first section details how cavity-ring down spectroscopy, previously used to make gas-phase measurements, is applied to liquids with great success. It is possible to measure absorption coefficients as small as 10−6 cm−1 in solution. These measurements can be performed while stirring or flowing the solution. Owing to the nature of ring-down, spatial resolution is demonstrated by monitoring diffusion. Multiplexed measurements (multiple wavelengths at the same time) are shown to be feasible. Ultratrace (parts per billion and below) kinetic measurements reveal the role that solvent plays in the reaction of methylene blue with ascorbic acid.; The second section deals with surface chemistry. Nitrogen molecules are scattered from a Ni(111) surface and their resulting exit angles and internal energy distributions are measured. We gain insight into the potential at the Ni(111) surface. N2 product internal-state distributions are recorded for the steady-state reactions of NO with H2 and NH3 on the Pt(100) surface. We find that contrary to previous belief N2 is produced through different mechanisms in each case. |
