It is observed that for many reactions the rate constant nearly doubles for a rise in temperature of how much?

1. A general empirical observation in kinetics relates rate to temperature. 2. For a rise of about 10 degrees, the rate constant becomes nearly double. 3. This is explained by the larger fraction of molecules crossing $E_a$ as T rises. _Source: syllabus Chemistry Ch 3 "Chemical Kinetics", p.17_