Use this chemistry calculator to reproduce a named relationship with explicit quantities and units for study, laboratory planning, or an independent numerical check.

Rate constant k (M/s)

Required number input.

Reactant A concentration (M)

Required number input.

Reactant B concentration (M)

Required number input.

Reaction order A

Required number input.

Reaction order B

Required number input.

Compute the reaction rate from the rate constant and reactant concentrations raised to their reaction orders. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Reaction rate (M/s)

The resulting reaction rate returned as a number.

• Kinetic results assume the selected rate law and constant conditions over the calculation interval. Reaction order, catalyst state, mixing, temperature, competing pathways, and transport limitation must be established independently.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check units and significant figures, compare the result with limiting cases, and use measured or source-specific constants where available. Laboratory, safety, and regulatory decisions require validated methods and appropriate uncertainty analysis.

• Pseudo First Order Rate

  Compute the observed pseudo first order rate constant for a second order reaction with one reactant in large excess.

• First Order Half-Life

  Compute the half-life of a first order reaction as the natural logarithm of two divided by the rate constant.

• Hess Law Enthalpy

  Compute the overall reaction enthalpy from Hess law as the summed product enthalpies minus the summed reactant enthalpies.