Calculate the number of moles based on mass and molar mass, or particles and Avogadro's number.
Mass to Moles
Moles to Mass
Particles to Moles
Moles to Particles
Enter values to see the result
Understanding Moles in Chemistry
The mole (symbol: mol) is the SI unit of amount of substance. It's a fundamental concept in chemistry used to quantify the number of elementary entities, such as atoms, molecules, ions, or electrons, in a sample. A mole is defined as the amount of substance that contains exactly 6.02214076 × 1023 elementary entities. This number is known as Avogadro's constant (NA).
Working with individual atoms or molecules is impractical due to their incredibly small size and number. The mole provides a convenient bridge between the microscopic world of atoms and molecules and the macroscopic world of measurable quantities like mass.
Key Concepts and Formulas:
Molar Mass (M): The mass of one mole of a substance, typically expressed in grams per mole (g/mol). It's numerically equal to the atomic mass or molecular mass of the substance in atomic mass units (amu). For example, the molar mass of water (H2O) is approximately 18.015 g/mol.
Avogadro's Number (NA): The number of elementary entities (atoms, molecules, etc.) in one mole of a substance. Its value is approximately 6.022 × 1023 mol-1.
How This Calculator Works:
This calculator simplifies common mole calculations:
Mass to Moles: If you know the mass of a substance and its molar mass, you can find the number of moles using the formula:
Moles (mol) = Mass (g) / Molar Mass (g/mol)
Moles to Mass: Conversely, if you know the number of moles and the molar mass, you can calculate the mass:
Mass (g) = Moles (mol) × Molar Mass (g/mol)
Particles to Moles: If you know the number of particles (atoms, molecules, ions) and Avogadro's number, you can determine the number of moles:
Moles (mol) = Number of Particles / Avogadro's Number (particles/mol)
Moles to Particles: If you know the number of moles and Avogadro's number, you can calculate the number of particles:
Number of Particles = Moles (mol) × Avogadro's Number (particles/mol)
Practical Applications:
Mole calculations are essential in various fields:
Chemical Reactions: Stoichiometry, predicting reactant and product amounts.
Solution Chemistry: Preparing solutions of specific concentrations (molarity).
Analytical Chemistry: Determining the composition of unknown substances.
Industrial Processes: Manufacturing chemicals, pharmaceuticals, and materials.
Understanding and accurately calculating moles is a cornerstone of successful chemistry.
var avogadroConstant = 6.02214076e23; // Use var as requested
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document.getElementById("molesToMassInputs").style.display = "none";
document.getElementById("particlesToMolesInputs").style.display = "none";
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document.getElementById("avogadroNumber").value = avogadroConstant; // Ensure it's set correctly
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document.getElementById("molesToParticlesInputs").style.display = "block";
document.getElementById("avogadroNumberParticles").value = avogadroConstant; // Ensure it's set correctly
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function calculateMoles() {
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var selectedType = document.getElementById("calculationType").value;
var calculatedValue = NaN;
var unit = "";
// Clear previous result and styling
resultDiv.textContent = "Enter values to see the result";
resultDiv.style.backgroundColor = "var(–success-green)"; // Reset to default
if (selectedType === "massToMoles") {
var mass = parseFloat(document.getElementById("massValue").value);
var molarMass = parseFloat(document.getElementById("molarMassValue").value);
if (!isNaN(mass) && !isNaN(molarMass) && molarMass !== 0) {
calculatedValue = mass / molarMass;
unit = " mol";
}
} else if (selectedType === "molesToMass") {
var moles = parseFloat(document.getElementById("molesValueMass").value);
var molarMass = parseFloat(document.getElementById("molarMassValueMass").value);
if (!isNaN(moles) && !isNaN(molarMass)) {
calculatedValue = moles * molarMass;
unit = " g";
}
} else if (selectedType === "particlesToMoles") {
var particles = parseFloat(document.getElementById("particleCount").value);
var avogadro = parseFloat(document.getElementById("avogadroNumber").value); // Read from input in case it's modified
if (!isNaN(particles) && !isNaN(avogadro) && avogadro !== 0) {
calculatedValue = particles / avogadro;
unit = " mol";
}
} else if (selectedType === "molesToParticles") {
var moles = parseFloat(document.getElementById("molesValueParticles").value);
var avogadro = parseFloat(document.getElementById("avogadroNumberParticles").value); // Read from input
if (!isNaN(moles) && !isNaN(avogadro)) {
calculatedValue = moles * avogadro;
unit = " particles"; // e.g., atoms, molecules
}
}
if (!isNaN(calculatedValue)) {
// Format scientific notation for particle counts if applicable
if (selectedType === "molesToParticles" && calculatedValue >= 1e6) {
resultDiv.textContent = calculatedValue.toExponential(4) + unit;
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resultDiv.textContent = calculatedValue.toExponential(4) + unit;
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// Use toFixed for potentially better precision for mass/moles
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resultDiv.textContent = "Invalid input. Please check your values.";
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