Chemical PE

CRITICAL: Ensure temperature is in absolute units (K or °R), not Celsius or Fahrenheit. The gas constant R must match the units of activation energy. Common PE exam approach: given two rate constants at different temperatures, use the two-temperature form to find activation energy.

On the PE exam, Bernoulli appears frequently in fluid mechanics problems. Remember it only applies to incompressible, steady flow along a streamline. Watch for problems involving tanks, pipes, and pumps. Always check if friction losses are given or if you need to calculate them separately using Darcy-Weisbach or other friction equations.

CRITICAL: Always use absolute temperatures (Kelvin or Rankine). The Carnot efficiency represents the theoretical maximum - actual heat engines will always have lower efficiency. Common on thermodynamics problems as a benchmark for comparing real cycles.

The PE exam often presents this in integrated form: ln(P2/P1) = (ΔH_vap/R)(1/T1 - 1/T2). Watch for temperature units - must be absolute (K or °R). Remember that higher temperature gives higher vapor pressure. Often used with Antoine equation for more precise vapor pressure calculations.

The Colebrook equation requires iterative solution - never appears as a direct calculation on PE exam. More likely to see Moody diagram lookups or approximations like Swamee-Jain. If given, use Excel Goal Seek or successive approximation starting with f = 0.02.