Determination of the rate parameters and products for the reaction of hydroxyl radicals with nitric acid

The discharge flow-EPR technique has been used to measure the rate constant and the product distribution for the reaction of OH with HNO3, which is important for stratospheric modeling. The rate constant is found to be (7.3±2)×10−15 exp[876±85)/T] cm3 molecule−1 s−1 in the range 251–403 K. Besides, the in situ titration of NO3 by NO has shown that the reaction of OH with HNO3 only produces NO3 and H2O at room temperature.