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🔬 ScienceFree
Combined gas law final volume calculator
See what volume a gas takes when pressure and temperature change together: 5 litres at 2 atm and 250 K become 20 litres at 1 atm and 500 K.
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Cryoscopic constant calculator
Recover a solvent's freezing-point constant from your own measurement: a depression of 0.93 K at 0.5 mol/kg with a van 't Hoff factor of 1 gives a Kf of 1.86…
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Decay constant calculator
Switch between the three ways of describing exponential decay: a half-life of 10 time units gives a decay constant of about 0.0693 per unit and a mean lifetime…
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Degree of dissociation calculator
Turn a measured van 't Hoff factor into the share of an electrolyte that actually ionizes: a factor of 1.8 for a salt that splits into two ions means a degree…
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Dilution factor calculator
Find how many times a stock gets diluted and how much diluent to add: 1 mL brought up to 10 mL is a tenfold dilution with 9 mL of diluent, a 1:9 mix.
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Degree of dissociation calculator
Turn an equilibrium constant and a starting concentration into the share that splits apart: Kc 0.05 with 0.1 mol/L gives α 0.5, so 50 % dissociates.
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Empirical formula from percent composition calculator
Turn mass percentages into the simplest whole-number formula: 11.19 % hydrogen and 88.81 % oxygen, with their atomic masses, give H2O.
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Heat of formation from reaction calculator
Solve for the missing heat of formation in a balanced equation: methane combustion at −890 kJ/mol, with −393.5 for carbon dioxide, −285.8 for water and 0 for…
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Molar enthalpy calculator
Turn a calorimeter's total heat into a molar enthalpy: −890 kJ measured for 1 mol reacted is −890 kJ/mol, and released heat keeps its negative, exothermic sign.
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Equilibrium constant from Gibbs calculator
Turn a standard Gibbs energy change into an equilibrium constant: −10,000 J/mol at 298.15 K gives K above one, so products are favored, while a ΔG° of zero…
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Equilibrium yield calculator
See how close a reversible reaction gets to full conversion: 75 mol of product at equilibrium out of a theoretical maximum of 100 mol is a 75% equilibrium…
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Formula units calculator
Turn grams of a salt into a count of formula units: 58.44 g of sodium chloride at 58.44 g/mol is exactly one mole, or 6.02214076 × 10²³ formula units.
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Fraction of molecules above Ea calculator
Estimate the share of molecules with enough energy to clear a reaction barrier: at 50,000 J/mol and 298.15 K only about 1.7 × 10⁻⁹ of them do, and that fraction…
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Freezing point depression calculator
Predict how far a solution's freezing point falls, in kelvin: 0.5 mol/kg of a non-electrolyte in water, with a Kf of 1.86, gives a drop of 0.93 K, and a strong…
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Fuel energy content calculator
Find the total energy a fuel can release: 2 kg of fuel with an energy density of 45 MJ/kg holds 90 MJ.
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Effusion remaining fraction calculator
See how a pinhole leak changes a gas mixture: with hydrogen at 2.016 g/mol and oxygen at 32 g/mol, at a time ratio of 0.5 roughly 14% of the hydrogen is left…
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Gas stoichiometry volume calculator
Predict how much gas a reaction gives off at your conditions: 1 mol of reactant with a 1:1 gas product at 1 atm and 273.15 K yields about 22.4 litres, and any…
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Gas volume at STP calculator
Turn moles of gas into litres at classic STP: 1 mol fills 22.4 L and 2.5 mol fill 56 L at 0 °C and 1 atm, the molar volume used in textbook gas stoichiometry.
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Gas temperature from P, V, n calculator
Recover the absolute temperature of an ideal gas: 1 mol at 1 atm in 22.414 L sits at about 273 K, the ice point.
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Gas volume at NTP calculator
One mole of ideal gas fills 24.0 litres at NTP, so the volume is simply the moles times 24.0. Enter the amount of gas and read the litres at 20 °C and 1 atm…
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Gibbs free energy calculator
For ΔH of −92.4 kJ/mol, ΔS of −0.1987 kJ/(mol·K) and 298.15 K, ΔG comes out at −33.157595 kJ/mol, which is spontaneous.
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Grams of product from moles calculator
Two moles of water at 18.015 g/mol make 36.03 grams of product. Enter the moles from your mole-ratio step and the product's molar mass to get the mass in grams…
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Grams of solute for molarity calculator
A 0.5 M sodium chloride solution in 0.25 litres needs 0.125 moles, which is 7.305 grams at 58.44 g/mol.
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Instantaneous rate from tangent calculator
Get the reaction rate at one moment from two close readings: 0.85 mol/L at 10 s and 0.8 mol/L at 12 s give 0.025 mol/L per second, the local tangent rather than…
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Equilibrium constant at new temperature
Find how an equilibrium constant shifts with temperature: a K of 0.05 at 298.15 K with a reaction enthalpy of −58000 J/mol falls to 0.0015616472 at 350 K, as an…
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Kp from partial pressures calculator
Work out Kp from one list of equilibrium pressures: for N2 + 3H2 ⇌ 2NH3 at 0.5, 1.5 and 0.1 atm, with reactants entered as negative coefficients, Kp is…
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Ksp from solubility calculator
Turn a molar solubility into a solubility product: a 1:1 salt such as silver chloride that dissolves to 0.01 mol/L has a Ksp of 0.0001, while calcium fluoride…
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Le Chatelier pressure shift calculator
See which way an equilibrium moves when you raise the pressure: ammonia synthesis has 4 moles of gas on the reactant side and 2 on the product side, so it…
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Limiting reagent from masses calculator
Tell which of two weighed reactants runs out first: 10 g of hydrogen at 2 g/mol with coefficient 2 against 10 g of oxygen at 32 g/mol with coefficient 1 makes…
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Mass percent to molality calculator
A 10% sodium chloride solution, with a molar mass of 58.44 g/mol, is about 1.901 mol/kg. Convert the weight percent printed on a bottle into the molality that…
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Mass percent to ppm converter
0.1% by mass is 1000 ppm, or 1,000,000 ppb. Turn the weight percent on a bottle or certificate into the ppm and ppb that environmental, drinking-water and food…
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Mass to gas volume calculator
32 g of oxygen at 1 atm and 273.15 K fill about 22.4 L, one mole of gas. Enter a gas mass, its molar mass, the pressure and the temperature in kelvin to get the…
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Mass-to-mass stoichiometry calculator
4 g of hydrogen give 36 g of water. Enter the reactant mass, both molar masses and the two coefficients from your balanced equation, and get the theoretical…
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mg/L to molarity calculator
5844 mg/L of sodium chloride, at 58.44 g/mol, is 0.1 mol/L. Turn the milligrams per litre on a water-quality sheet or lab assay into the molarity that…
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Molar concentration calculator
Half a mole of solute in 2 L of solution is 0.25 mol/L. Enter moles and volume, or a weighed mass with its molar mass, and get the molarity of the solution you…
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Molar mass from boiling point elevation
With a Kb of 0.512, a rise of 0.256 K from 5 g of solute in 0.1 kg of solvent points to 100 g/mol.
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Molar mass from gas density calculator
A gas with a density of 1.429 g/L at 1 atm and 273.15 K has a molar mass of about 32 g/mol. Enter density, pressure and temperature in kelvin to identify an…
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Molarity from moles and volume calculator
One mole dissolved to 1 L is 1 M, and half a mole made up to 2 L is 0.25 mol/L. When the moles are already known, divide by the final volume in litres for a…
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Molarity to molality calculator
1 M sodium chloride with a density of 1.04 g/mL is about 1.019 mol/kg. Turn a stock solution's molarity into the molality that freezing-point and boiling-point…
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Mole fraction to mass percent calculator
A solute mole fraction of 0.5 with molar masses of 32 and 18 g/mol means 64% of the mass is solute.
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Osmolarity calculator
0.1 mol/L sodium chloride splits into 2 particles and gives 0.2 Osm/L, twice what glucose at the same molarity gives.
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Oxygen for combustion calculator
One mole of propane, C3H8, needs 5 moles of oxygen to burn completely and gives 3 moles of carbon dioxide and 4 of water.
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Particles to moles calculator
6.02214076 × 10²³ particles are exactly 1 mole: type how many atoms, molecules or ions you have and get the amount in moles, divided by the fixed Avogadro…
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Percent composition calculator
Water is about 11 % hydrogen and 89 % oxygen by mass: type a formula and see each element's share of the molar mass, with the atoms counted, the atomic weight…
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Percent to molarity calculator
37 % hydrochloric acid with a density of 1.19 g/mL and a molar mass of 36.46 g/mol is about 12 mol/L: enter the bottle's percent, density and molar mass to get…
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Percent water in hydrate calculator
A 5 g hydrate that leaves 3.2 g of dry salt after heating held 36 % water: enter the two crucible weighings and get the water lost, the percent water and the…
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Strong acid pH calculator
0.1 mol/L hydrochloric acid has a pH of 1: enter the molarity of a strong monoprotic acid such as HCl or HNO3 and get the pH as minus the logarithm of that…
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PPB concentration calculator
0.001 g of solute in 1000 g of solution is 1000 ppb: enter the solute mass and the total mass in the same unit and get the parts per billion and the mass…
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PPM from molarity calculator
0.001 mol/L of sodium chloride (58.44 g/mol) at a density of 1 g/mL is 58.44 ppm by mass. Enter molarity, molar mass and density, and see the solute and…
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Equilibrium direction predictor
With Q at 0.25 and K at 4, Q is below K, so the reaction shifts forward toward products. Enter the reaction quotient and the equilibrium constant to see the…
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Rate constant from half-life calculator
A first-order half-life of 10 seconds gives a rate constant of 0.0693147181 per second, because k is ln 2 divided by the half-life.
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Graham's law calculator
Hydrogen at 2.016 g/mol effuses 3.9840953644 times as fast as oxygen at 32 g/mol, about four times, because the effusion rate falls with the square root of…
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Reaction order from rate data calculator
If doubling the concentration from 0.1 to 0.2 raises the initial rate from 0.01 to 0.04, the reaction is second order in that reactant.
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Solution boiling point calculator
Water that boils at 100 °C, with Kb of 0.512 and a 0.5 mol/kg solute, boils at 100.256 °C as a solution.
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Specific heat from calorimetry calculator
A 100 g sample that absorbs 4184 J while warming by 10 degrees has a specific heat of 4.184 J/g per degree, a water-like value.
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Stock solution volume calculator
To make 100 mL of a 1 M solution from a 10 M stock, take 10 mL of stock and add 90 mL of diluent. Enter the stock concentration, the target and the final volume…
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Theoretical moles of product calculator
When one mole of nitrogen limits the ammonia synthesis, at most two moles of ammonia can form. Enter the limiting moles and both balanced coefficients to get…
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Theoretical yield from limiting reactant calculator
Two moles of hydrogen limiting the water synthesis give at most 36 g of water. Enter the limiting moles, both coefficients and the product's molar mass to get…
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Total ion concentration calculator
A 0.10 mol/L sodium chloride solution holds 0.20 mol/L of ions, because each formula unit splits into two.
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Total pressure of gas mixture calculator
The partial pressures of oxygen, nitrogen and argon in dry air add up to a total of 1 atm: that is Dalton's law.
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