Sum of atomic masses from the periodic table (e.g., C=12.01, O=16.00).
Mass (grams)
Moles (mol)
Number of Particles (atoms/molecules)
For particles, you can use 'e' notation (e.g., 6.02e23).
Calculation Results
Moles ($n$):–
Mass ($m$):–
Particles ($N$):–
Step-by-Step Logic:
Mastering the Mole Calculation Worksheet
In chemistry, the mole is the bridge between the microscopic world of atoms and the macroscopic world of grams. This Mole Calculation Worksheet tool helps students and chemists instantly convert between mass, moles, and the number of particles (atoms or molecules) using standard stoichiometric principles.
Key Formulas Used
To perform these calculations manually on your worksheet, you need three primary variables: Mass ($m$), Molar Mass ($M$), and Avogadro's Number ($N_A$).
1. Moles ($n$) = Mass ($m$) / Molar Mass ($M$)
2. Mass ($m$) = Moles ($n$) × Molar Mass ($M$)
3. Particles ($N$) = Moles ($n$) × Avogadro's Constant ($6.022 \times 10^{23}$)
How to Use This Calculator
Determine Molar Mass: Calculate the molar mass of your substance by adding the atomic masses from the periodic table.
Select Your Known Variable: Are you starting with grams (mass), moles, or a count of atoms/molecules? Select this from the dropdown.
Enter the Value: Input your known number. For very large numbers of particles, you can use scientific notation (e.g., enter "3.5e24" for $3.5 \times 10^{24}$).
Common Mole Conversion Examples
Substance
Molar Mass
Input (Known)
Result (Unknown)
Carbon ($C$)
12.01 g/mol
24.02 g
2.0 moles
Sodium Chloride ($NaCl$)
58.44 g/mol
0.5 moles
29.22 g
Gold ($Au$)
196.97 g/mol
1 mole
$6.022 \times 10^{23}$ atoms
Understanding Avogadro's Number
Avogadro's number ($6.022 \times 10^{23}$) is the number of units in one mole of any substance. Just as a "dozen" always equals 12 items, a "mole" always equals $6.022 \times 10^{23}$ particles. This constant allows chemists to count atoms by weighing them.
function updateInputLabel() {
var type = document.getElementById('inputType').value;
var label = document.getElementById('inputValueLabel');
var input = document.getElementById('inputValue');
if (type === 'mass') {
label.innerText = 'Enter Mass (grams)';
input.placeholder = 'e.g., 50';
} else if (type === 'moles') {
label.innerText = 'Enter Moles (mol)';
input.placeholder = 'e.g., 2.5';
} else if (type === 'particles') {
label.innerText = 'Enter Number of Particles';
input.placeholder = 'e.g., 6.022e23';
}
}
function formatScientific(num) {
if (num === 0) return "0";
if (num > 10000 || num < 0.001) {
var expString = num.toExponential(3);
var parts = expString.split('e');
return parts[0] + ' × 10' + parseInt(parts[1]) + '';
}
return num.toFixed(4);
}
function calculateMole() {
// Inputs
var molarMass = parseFloat(document.getElementById('molarMass').value);
var inputValRaw = document.getElementById('inputValue').value;
var inputType = document.getElementById('inputType').value;
// Handle Avogadro's Constant
var avogadro = 6.022e23;
// Validation
if (isNaN(molarMass) || molarMass <= 0) {
alert("Please enter a valid positive Molar Mass.");
return;
}
// Clean input value (allow scientific notation like 1.5e23)
var inputVal = parseFloat(inputValRaw);
if (isNaN(inputVal) || inputVal < 0) {
alert("Please enter a valid positive number for the input value.");
return;
}
var moles = 0;
var mass = 0;
var particles = 0;
var explanation = "";
// Calculation Logic based on Input Type
if (inputType === 'mass') {
mass = inputVal;
moles = mass / molarMass;
particles = moles * avogadro;
explanation = "Started with Mass (" + mass + "g). 1. Moles = " + mass + " / " + molarMass + " = " + moles.toExponential(3) + " mol.2. Particles = " + moles.toExponential(3) + " × " + avogadro.toExponential(3) + ".";
} else if (inputType === 'moles') {
moles = inputVal;
mass = moles * molarMass;
particles = moles * avogadro;
explanation = "Started with Moles (" + moles + " mol). 1. Mass = " + moles + " × " + molarMass + " = " + mass.toFixed(3) + " g.2. Particles = " + moles + " × " + avogadro.toExponential(3) + ".";
} else if (inputType === 'particles') {
particles = inputVal;
moles = particles / avogadro;
mass = moles * molarMass;
explanation = "Started with Particles (" + inputValRaw + "). 1. Moles = " + inputValRaw + " / " + avogadro.toExponential(3) + " = " + moles.toExponential(3) + " mol.2. Mass = " + moles.toExponential(3) + " × " + molarMass + ".";
}
// Display Results
document.getElementById('resMoles').innerHTML = formatScientific(moles) + " mol";
document.getElementById('resMass').innerHTML = formatScientific(mass) + " g";
document.getElementById('resParticles').innerHTML = formatScientific(particles) + " particles";
document.getElementById('calcExplanation').innerHTML = explanation;
document.getElementById('resultsArea').style.display = 'block';
}