You can use these calculators to calculate electrode potential, gravitational force, pH, chemistry units conversion, and more..

General Chemistry Refresher: Redox Reactions Calculator
Calculate the electrode potential for a half-reaction, with inputs being the concentrations and stoichiometric coefficients of the reactants and products, and the number of electrons transferred.

Gravitational Force Calculator
The "Gravitational Force Calculator" uses scientific notation to display either very large- or small numbers.

Odav OnLine LiveCalculator - [ Math & Science ] Periodic Table of Chemical Elements
Simply mouse over to view the value of each chemical element.

Polyatomic Ion Calculator
The purpose of this calculator is to determine the scientific name of the ionic molecule entered.

Scientific calculator for chemists @ periodni.com
Calc4Chem is a JavaScript scientific calculator for chemists. This calculator can be used as common scientific calculator (sin, cos, log, power, root, memory), but it also includes a molecular weight calculator and the tables with various physical and chemical constants. The calculator contains a list with task history, storing all the recent inputs and results. Scientific calculator displays the numbers rounded to a user-specified number of decimal places.
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The Arrhenius Equation
This calculator calculates the effect of temperature on reaction rates using the Arrhenius equation.

Unit Conversion Table
Simply choose an entry from the "From:" pop-up menu and one from the "To:" pop-up menu and the conversion will appear in the output window below your selection.

pH Calculator - Calculates pH of a Solution - Chemistry Online Education
Calculates pH of any solution.