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

Q

Reaction quotient Q computed from current conditions.

K

Equilibrium constant K.

Compare the reaction quotient Q against the equilibrium constant K to determine the direction of shift. 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]

Shift direction

Direction the reaction proceeds: toward reactants, toward products, or no change.

• Equilibrium expressions must match the balanced reaction and selected standard state. Concentrations or partial pressures may not equal activities at non-ideal conditions, and a calculated equilibrium constant does not describe how quickly equilibrium is reached.
• 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.

• Qc vs Kc Checker

  Compare the concentration-based quotient Qc against Kc to determine whether products or reactants are favored going forward.

• Solubility Product Quotient Calculator

  Compute the reaction quotient Q = [A]ˣ[B]ʸ for a dissolving salt and compare it against Ksp.

• Van't Hoff K2

  Compute the natural log of an equilibrium constant at a second temperature with the van 't Hoff relation from the reaction enthalpy and a known value at a first temperature.