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

Limiting moles (mol)

Moles of the limiting reagent consumed.

Limiting coefficient

Coefficient of the limiting reagent; must be nonzero.

Excess coefficient

Coefficient of the excess reagent; must be nonzero.

Available moles (mol)

Starting moles of the excess reagent.

Compute the moles of excess reagent left over after the limiting reagent is fully consumed. 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]

Remaining moles (mol)

Moles of excess reagent left after reaction.

• Stoichiometric results assume the balanced reaction, stated purity, and complete conversion to the selected products. Yield, selectivity, side reactions, moisture, and measurement uncertainty must be handled separately.
• 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.

• Limiting Reagent Excess Amount Calculator

  Compute the leftover moles of an excess reagent after complete consumption of the limiting reagent.

• Excess Reagent Mass Remaining Calculator

  Convert the leftover moles of an excess reagent into mass using its molar mass.

• Buffer pH After Addition

  Compute the buffer pH after adding strong base as pKa plus log10 of conjugate base over remaining weak acid.