Chemistry Solver
Seven small chemistry calculators on one page. Type a formula or the numbers you know and get the answer with the working. Nothing leaves your browser.
Molar mass of a formula
Type a formula with element symbols. Brackets, nesting and hydrates work, for example Ca(OH)2, Al2(SO4)3 or CuSO4.5H2O. Symbols are case-sensitive.
Percent composition by mass
Shows how much of the mass of one mole of the compound comes from each element.
Grams, moles and particles
Convert between grams, moles and number of particles (molecules, formula units or atoms). Grams need a molar mass: type a formula, or type the molar mass yourself (it wins if you fill both).
Equation balancer
Write the reaction with an arrow (->, = or the arrow symbol) and plus signs. Do not type coefficients. Ions, charges and redox half-reactions are not supported.
Solutions: molarity and dilution
Molarity (M = n / V)
Fill two of the three boxes and leave one empty. The empty one is calculated. For grams, type a formula or a molar mass.
Dilution (C1 × V1 = C2 × V2)
Fill three of the four boxes and leave one empty. C1 and V1 are the stock solution; C2 and V2 are the diluted solution.
pH, pOH and concentrations (25 °C)
Convert between pH, pOH, [H+] and [OH-]
Uses pH + pOH = 14 and Kw = 1 × 10-14, which is true at 25 °C only. Concentrations are in mol/L.
pH of a strong acid or strong base
Assumes complete dissociation. Weak acids, weak bases and buffers are not covered.
Ideal gas law (PV = nRT)
Fill three of the four boxes and leave one empty. R = 8.314462618 J/(mol·K) = 0.082057 L·atm/(mol·K). Temperature must be above absolute zero.
Typing questions in words and solving from a photo are planned. Today this tool solves questions written as formulas.
How to Use the Chemistry Solver
Pick a tab for the kind of problem you have, fill in what you know and press the button. The result, with the numbers used, appears underneath.
- Choose a tab: Use
Molar mass,Percent composition,Moles,Equation balancer,Solutions,pHorIdeal gas. - Enter formulas with element symbols: Write
H2O,Ca(OH)2orCuSO4.5H2O. Symbols are case-sensitive:Cois cobalt,COis carbon monoxide. Tap an example to fill the box. - Leave one box empty when solving: In the solutions and gas law tabs, fill all values you know and leave the one you want empty. Pick the unit next to each value.
- Read the result and the working: Each answer shows the unit and how it was found. Use the Copy button to take the answer with you.
Key Features
- Molar mass with a breakdown: Brackets, nested groups and hydrates are read, and every element is listed with its count, atomic weight and subtotal.
- Percent composition: The share of each element in one mole of a compound, by mass.
- Equation balancer with exact arithmetic: Finds the smallest whole-number coefficients by solving the atom-count equations with fractions, so there is no rounding. If there is no solution or more than one, it says so.
- Moles, solutions and dilution: Convert grams, moles and particles, work out molarity or the mass of solute needed, and solve
C1 V1 = C2 V2for any one value. - pH and gas law: Convert between pH, pOH, [H+] and [OH-], find the pH of a strong acid or base, and solve
PV = nRTfor any one variable with unit choices. - Private: All calculations happen in your browser. Nothing you type is sent anywhere or stored.
What This Tool Can and Cannot Do
This tool works with formulas written with element symbols, and with the numbers you type. It does not read word problems or photos yet. Check that the units you pick match your problem.
Formulas are case-sensitive. The balancer handles neutral substances only: ions, charges and redox half-reactions are not supported, and some equations have more than one valid balanced form, in which case it will not guess. The pH tab assumes 25 °C and strong acids and bases; weak acids, weak bases and buffers are not covered.
Atomic weights are the IUPAC abridged standard atomic weights (2021 table) rounded as IUPAC prints them. Elements with no stable isotopes have no standard weight, so the mass number of a long-lived isotope is used and marked with an asterisk. Ranges in real samples are wider than the printed value suggests, so answers are only as exact as the data.
Frequently Asked Questions
Why are formulas case-sensitive?
Element symbols are one capital letter, sometimes followed by a lower-case letter. Co is cobalt but CO is carbon and oxygen, and Cl is chlorine but CL is not an element. Reading the letters exactly as typed avoids silent mistakes.
Why does the molar mass differ slightly from my textbook?
Textbooks round atomic weights differently or use older tables. This tool uses the IUPAC 2021 abridged values, for example sulfur is 32.06, so the answer can differ in the third decimal place.
Can the balancer handle ions and redox reactions?
No. It balances neutral substances by atom counts only. If an equation can be balanced in several independent ways, or cannot be balanced at all, it tells you instead of choosing an answer.
What temperature does the pH tab assume?
25 °C, where Kw is 1 × 10^-14 and pH + pOH = 14. At other temperatures Kw is different, so the numbers would change.
Why must temperature be above absolute zero in the gas law?
The ideal gas law uses kelvin. A Celsius value is converted by adding 273.15, and anything at or below 0 K (-273.15 °C) is rejected.
Is my data stored or sent anywhere?
No. Everything is calculated in your browser and nothing is saved when you close the page.