An essential tool for chemists and scientists to convert weight percentage concentration to molarity.
Molarity from Weight Percent Calculator
Enter the concentration of the solute in weight percent (%).
Enter the molar mass of the solute (e.g., NaCl is 58.44 g/mol).
Enter the density of the final solution (e.g., 1.05 g/mL).
Results
— M
Formula Used: Molarity (M) = (Weight Percent / 100) * Density (g/mL) / Molar Mass (g/mol) * 1000 (mL/L)
Mass of Solute (g)—
Mass of Solution (g)—
Volume of Solution (L)—
Molarity vs. Weight Percent
Legend:
Series 1: Molar Mass (g/mol)
Series 2: Solution Density (g/mL)
Sample Molarity Calculations
Weight Percent (%)
Solute Molar Mass (g/mol)
Solution Density (g/mL)
Calculated Molarity (M)
What is Molarity Calculation from Weight Percent?
Molarity is a fundamental concept in chemistry, representing the concentration of a solute in a solution. Specifically, it is defined as the number of moles of solute per liter of solution. The unit for molarity is moles per liter, commonly denoted as 'M'. Understanding how to calculate molarity from weight percent is crucial because many chemical compounds are prepared or sold based on their weight percentage concentration. This allows scientists to accurately determine the precise concentration needed for reactions, experiments, or formulations without needing to know the exact volume of the original solution, relying instead on its density and the solute's molar mass. It bridges the gap between practical, often weight-based measurements, and the mole-based calculations essential for stoichiometry and chemical kinetics.
Who Should Use It?
This calculation is indispensable for a wide range of individuals within scientific and industrial fields:
Chemists (Research & Development): Formulating new compounds, optimizing reaction conditions, and ensuring accurate reagent concentrations.
Laboratory Technicians: Preparing standard solutions for analytical testing, quality control, and experimental procedures.
Chemical Engineers: Designing and managing chemical processes in industrial settings, where precise concentration control is vital for safety and efficiency.
Students of Chemistry: Learning and applying fundamental chemical principles in academic settings.
Quality Control Analysts: Verifying the concentration of raw materials and finished products in industries like pharmaceuticals, food and beverage, and manufacturing.
Formulators: Developing products such as cleaning agents, cosmetics, and agricultural chemicals that rely on specific solution strengths.
Common Misconceptions
Several common misunderstandings can arise when working with molarity and weight percent:
Molarity = Weight Percent: This is incorrect. Molarity is a mole-based concentration (moles/liter), while weight percent is mass-based (mass of solute / mass of solution * 100). They are related but not interchangeable.
Density is Always 1 g/mL: While water has a density close to 1 g/mL, most other solutions do not. Ignoring or assuming incorrect density can lead to significant errors.
Molar Mass is Constant: The molar mass of a pure substance is constant. However, if the solute is a mixture or an ionic compound that dissociates, the effective molar mass for concentration calculations might need careful consideration.
"Percent" Always Means Weight Percent: While common, "percent" can sometimes refer to volume percent (v/v) or mass-volume percent (w/v), requiring clarification. This calculator specifically addresses weight percent (w/w).
Molarity from Weight Percent Formula and Mathematical Explanation
To calculate molarity (M) from weight percent (wt%), molar mass (MM), and solution density (ρ), we need to perform a series of conversions. The fundamental relationship is:
Molarity (M) = Moles of Solute / Volume of Solution (in Liters)
Let's break down how to get there:
Assume a convenient total mass of solution: The easiest assumption is 100 grams of the solution. This simplifies the weight percent calculation.
Calculate the mass of the solute: If we have 100 g of solution and it's X% solute by weight, then the mass of the solute is simply X grams.
Mass of Solute = (Weight Percent / 100) * Total Mass of Solution Assuming Total Mass = 100g: Mass of Solute = Weight Percent (in grams)
Calculate the moles of solute: Using the molar mass (MM) of the solute, we convert the mass of the solute to moles.
Moles of Solute = Mass of Solute / Molar Mass (MM)
Calculate the mass of the solution: If we assumed 100 g of solution, then the mass of the solution is 100 g.
Calculate the volume of the solution: Using the density (ρ) of the solution, we convert the mass of the solution to volume. Density is usually given in g/mL, so we'll get volume in mL.
Volume of Solution (mL) = Mass of Solution (g) / Density (g/mL)
Convert volume to Liters: Molarity requires volume in liters.
Volume of Solution (L) = Volume of Solution (mL) / 1000
Calculate Molarity: Now we have moles of solute and volume of solution in liters.
Molarity (M) = Moles of Solute / Volume of Solution (L)
Combining these steps, and using 100g of solution as our base:
Simplifying this yields the formula implemented in the calculator:
Molarity (M) = (Weight Percent / 100) * Density (g/mL) / Molar Mass (g/mol) * 1000
Variables Explained
Variables in Molarity Calculation
Variable
Meaning
Unit
Typical Range/Notes
Weight Percent (wt%)
Mass of solute divided by the total mass of the solution, multiplied by 100.
%
0.01% to 100%
Solute Molar Mass (MM)
The mass of one mole of the solute substance.
g/mol
Typically > 1 g/mol (e.g., H₂ is ~2 g/mol, complex molecules can be hundreds)
Solution Density (ρ)
The mass of the solution per unit volume.
g/mL
Often close to 1 g/mL for aqueous solutions, but varies significantly (e.g., 0.8 g/mL for some organic solvents, >1 g/mL for concentrated salts)
Molarity (M)
The final concentration of the solute in moles per liter of solution.
mol/L or M
Highly variable based on application.
Mass of Solute
The actual mass of the solute present in the solution.
g
Calculated value.
Mass of Solution
The total mass of the solute plus the solvent.
g
Calculated value (based on assumed 100g total).
Volume of Solution
The total volume occupied by the solution.
L
Calculated value.
Practical Examples (Real-World Use Cases)
Example 1: Preparing a Sodium Chloride (NaCl) Solution
A chemist needs to prepare 1 liter of a 0.5 M NaCl solution. They have a stock solution that is 15% NaCl by weight. The density of this stock solution is 1.1 g/mL. What volume of the stock solution is needed? (Note: This calculator finds Molarity, but understanding the inverse helps illustrate. We'll calculate the molarity of the stock first).
Inputs for Calculator:
Weight Percent: 15%
Solute Molar Mass (NaCl): 58.44 g/mol
Solution Density: 1.1 g/mL
Calculation using the tool (or manually):
Mass of Solute (assuming 100g solution) = 15 g
Mass of Solution = 100 g
Volume of Solution = 100 g / 1.1 g/mL = 90.91 mL = 0.09091 L
Moles of NaCl = 15 g / 58.44 g/mol = 0.2567 mol
Molarity = 0.2567 mol / 0.09091 L = 2.82 M
Interpretation: The stock solution has a molarity of approximately 2.82 M. To get 1 L of 0.5 M NaCl, the chemist would need to dilute this stock solution. They could use the dilution formula C1V1 = C2V2, where C1=2.82 M, C2=0.5 M, and V2=1 L, solving for V1 (volume of stock needed).
Example 2: Calculating Molarity of Concentrated Sulfuric Acid
Concentrated sulfuric acid (H₂SO₄) is often sold as a 98% solution by weight. Its density is approximately 1.84 g/mL. What is the molarity of this concentrated sulfuric acid?
Inputs for Calculator:
Weight Percent: 98%
Solute Molar Mass (H₂SO₄): 98.07 g/mol
Solution Density: 1.84 g/mL
Calculation using the tool:
Mass of Solute (assuming 100g solution) = 98 g
Mass of Solution = 100 g
Volume of Solution = 100 g / 1.84 g/mL = 54.35 mL = 0.05435 L
Moles of H₂SO₄ = 98 g / 98.07 g/mol = 0.9993 mol
Molarity = 0.9993 mol / 0.05435 L = 18.39 M
Interpretation: Concentrated sulfuric acid is highly concentrated, with a molarity of nearly 18.4 M. This high molarity underscores the need for extreme caution when handling it due to its corrosive nature and reactivity.
How to Use This Molarity from Weight Percent Calculator
Input Weight Percent: Enter the concentration of your solute as a percentage by weight (e.g., type 15 for 15%).
Input Solute Molar Mass: Find the molar mass of your solute from a periodic table or chemical reference. Ensure it's in grams per mole (g/mol).
Input Solution Density: Provide the density of the final solution in grams per milliliter (g/mL). This value is critical for converting mass to volume.
Click 'Calculate Molarity': The calculator will process your inputs.
Reading the Results:
Molarity (M): The primary result displayed prominently. This is the concentration of your solution in moles per liter.
Intermediate Values: The calculator also shows the calculated Mass of Solute, Mass of Solution (based on a 100g assumption), and Volume of Solution in Liters. These help understand the conversion steps.
Chart: Visualizes how Molar Mass and Density influence the final Molarity.
Table: Provides pre-calculated examples for quick reference.
Decision-Making Guidance:
The calculated molarity helps you determine if a solution meets the requirements for an experiment, synthesis, or industrial process. You can use it to:
Confirm if a prepared solution has the desired concentration.
Calculate the necessary dilution factor for stock solutions.
Compare the strengths of different solutions.
Ensure safety compliance based on concentration thresholds.
Key Factors That Affect Molarity Results
Several factors influence the accuracy and interpretation of molarity calculations derived from weight percent:
Accuracy of Input Values: The most direct impact. Errors in measured weight percent, solute molar mass, or solution density will propagate to the final molarity. Precise measurements are paramount.
Temperature Effects on Density: Solution density is temperature-dependent. The density provided must correspond to the temperature at which the solution is being used or prepared. Significant temperature deviations can alter the true molarity.
Purity of Solute: The provided molar mass assumes a pure solute. Impurities will affect the actual molar mass and potentially the density, leading to inaccuracies if not accounted for. This is especially relevant when using technical-grade chemicals.
Dissociation of Solutes: For ionic compounds (like NaCl or H₂SO₄), the substance dissociates into ions in solution. While molarity is typically calculated based on the formula unit's molar mass, the colligative properties (like osmotic pressure) depend on the total number of solute particles (ions). This calculator provides molarity based on the compound's formula mass.
Hydration/Solvation: Some solutes incorporate water molecules into their crystal structure (hydrates) or associate with solvent molecules. This affects the effective molar mass and the overall density, requiring specific data for hydrated forms if applicable.
Volume Changes Upon Mixing: Ideally, volumes are additive. However, mixing a solute and solvent can sometimes result in a final solution volume that is slightly different from the sum of the individual components' volumes. This effect is usually minor for dilute solutions but can become significant at high concentrations. The density measurement inherently accounts for this.
Pressure Effects: While generally negligible for liquid solutions under typical laboratory conditions, extreme pressure variations can slightly alter density and thus molarity.
Frequently Asked Questions (FAQ)
Q1: Can I use this calculator for volume percent?
A1: No, this calculator is specifically designed for converting weight percent (w/w) to molarity. Volume percent (v/v) requires different input data (volumes) and calculation methods.
Q2: What if my solute is a gas dissolved in a liquid?
A2: Calculating molarity for gas solutions typically involves partial pressures and Henry's Law, which is different from the weight percent method used here. This calculator is best suited for solid solutes or liquids dissolved in liquids.
Q3: How accurate is the molarity calculation?
A3: The accuracy depends directly on the accuracy of the input values (weight percent, molar mass, density) and the assumption that the solute is pure and does not undergo unexpected reactions or significant volume changes upon mixing.
Q4: What is the difference between molarity and molality?
A4: Molarity (M) is moles of solute per liter of solution. Molality (m) is moles of solute per kilogram of solvent. They are related but differ in their volume/mass basis.
Q5: Where can I find the molar mass of a chemical?
A5: Molar masses can be found on the periodic table (for elements) and in chemical handbooks, online chemical databases (like PubChem, ChemSpider), or on the Safety Data Sheet (SDS) provided by the chemical manufacturer.
Q6: What if the density isn't provided? Can I assume it's 1 g/mL?
A6: Never assume the density is 1 g/mL unless you are working with pure water or a very dilute aqueous solution. Densities vary significantly based on the solute and concentration. If density is unknown, you'll need to measure it or find a reliable reference value for your specific solution concentration and temperature.
Q7: Does the calculator handle mixtures as solutes?
A7: This calculator assumes a single, pure solute with a defined molar mass. If your "solute" is actually a mixture, you would need to determine the effective average molar mass of the mixture components based on their proportions within the mixture itself.
Q8: How does temperature affect the calculation?
A8: Temperature primarily affects the density of the solution. Most density values are reported at a specific temperature (e.g., 20°C or 25°C). If your solution is at a different temperature, its density will likely change, affecting the final molarity calculation. Molar mass is generally considered temperature-independent.
var weightPercentInput = document.getElementById("weightPercent");
var soluteMolarMassInput = document.getElementById("soluteMolarMass");
var solutionDensityInput = document.getElementById("solutionDensity");
var weightPercentError = document.getElementById("weightPercentError");
var soluteMolarMassError = document.getElementById("soluteMolarMassError");
var solutionDensityError = document.getElementById("solutionDensityError");
var molarityResult = document.getElementById("molarityResult");
var massSolute = document.getElementById("massSolute");
var massSolution = document.getElementById("massSolution");
var volumeSolution = document.getElementById("volumeSolution");
var tableBody = document.getElementById("tableBody");
var chartContext;
var molarityChart;
// Pre-populate sample data for the table
var sampleData = [
{ wp: 10, mm: 58.44, rho: 1.07, molarity: 0 },
{ wp: 15, mm: 58.44, rho: 1.1, molarity: 0 },
{ wp: 5, mm: 36.46, rho: 1.02, molarity: 0 }, // HCl example
{ wp: 98, mm: 98.07, rho: 1.84, molarity: 0 }, // H2SO4 example
{ wp: 20, mm: 40.00, rho: 1.22, molarity: 0 } // NaOH example
];
function updateChart(weightPercent, soluteMolarMass, solutionDensity) {
if (!chartContext) {
var canvas = document.getElementById("molarityChart");
chartContext = canvas.getContext("2d");
molarityChart = new Chart(chartContext, getChartConfig(weightPercent, soluteMolarMass, solutionDensity));
} else {
// Update existing chart data
molarityChart.data.datasets[0].data = getMolarMassSeries(weightPercent, soluteMolarMass, solutionDensity);
molarityChart.data.datasets[1].data = getDensitySeries(weightPercent, soluteMolarMass, solutionDensity);
molarityChart.options.scales.x.ticks.callback = function(value, index, values) {
return value + "%";
};
molarityChart.update();
}
}
function getMolarMassSeries(wp, mm, rho) {
var data = [];
for (var i = 1; i <= 100; i+=5) {
// Molar mass is constant for the purpose of this chart series, but we need data points for the x-axis
// Let's plot Molarity against Weight Percent for fixed MM and Rho
data.push(calculateMolarity(i, mm, rho));
}
return data;
}
function getDensitySeries(wp, mm, rho) {
// This series doesn't make direct sense as a separate line fluctuating with density unless we vary density.
// For demonstration, let's show how molarity changes if DENSITY were to change for a fixed WP and MM
// This might be confusing. A better chart would show M vs WP for FIXED MM and DENSITY.
// Let's revise the chart goal: show how Molarity changes with Weight Percent given fixed MM and Rho.
// The current chart structure implies two independent series changing.
// For simplicity, let's make the second series a reference line or remove it if it adds confusion.
// Let's try showing how Molarity changes if Molar Mass changes while WP and Rho are fixed.
var data = [];
var baseMolarity = calculateMolarity(wp, mm, rho);
var currentMM = mm;
for (var i = 1; i <= 100; i += 5) { // Hypothetical Molar Masses
data.push(calculateMolarity(wp, i, rho)); // Using i as hypothetical MM
}
return data;
}
function getChartConfig(wp, mm, rho) {
var xLabels = [];
for (var i = 1; i <= 100; i+=5) {
xLabels.push(i + "%");
}
// We are plotting Molarity vs Weight Percent. The other inputs (MM, Rho) are constants for a given calculation run.
// The chart should ideally show how Molarity changes if *one* of the inputs changes while others are fixed.
// Let's make the chart show M vs WP, with lines representing different FIXED MM and DENSITY values.
// Series 1: Fixed MM = input mm, varying WP
var series1Data = [];
for(var currentWP = 1; currentWP <= 100; currentWP += 5) {
series1Data.push(calculateMolarity(currentWP, mm, rho));
}
// Series 2: Fixed DENSITY = input rho, varying WP, but with a DIFFERENT FIXED Molar Mass (e.g., double the input mm)
var hypotheticalMM = mm * 2; // Example: compare with a heavier solute
var series2Data = [];
for(var currentWP = 1; currentWP <= 100; currentWP += 5) {
series2Data.push(calculateMolarity(currentWP, hypotheticalMM, rho));
}
// Series 3: Fixed Molar Mass = input mm, varying WP, but with a DIFFERENT FIXED Density (e.g., 1.2 * input rho)
var hypotheticalRho = rho * 1.2; // Example: compare with denser solution
var series3Data = [];
for(var currentWP = 1; currentWP (i + 1) * 5 + "%"), // 20 points from 5% to 100%
datasets: [
{
label: 'Molarity (Current: ' + mm.toFixed(2) + ' g/mol, ' + rho.toFixed(2) + ' g/mL)',
data: series1Data,
borderColor: 'rgb(0, 74, 153)',
backgroundColor: 'rgba(0, 74, 153, 0.1)',
tension: 0.1,
fill: false
},
{
label: 'Molarity (Hypothetical: ' + hypotheticalMM.toFixed(2) + ' g/mol, ' + rho.toFixed(2) + ' g/mL)',
data: series2Data,
borderColor: 'rgb(40, 167, 69)',
backgroundColor: 'rgba(40, 167, 69, 0.1)',
tension: 0.1,
fill: false
},
{
label: 'Molarity (Hypothetical: ' + mm.toFixed(2) + ' g/mol, ' + hypotheticalRho.toFixed(2) + ' g/mL)',
data: series3Data,
borderColor: 'rgb(255, 193, 7)', // Yellowish
backgroundColor: 'rgba(255, 193, 7, 0.1)',
tension: 0.1,
fill: false
}
]
},
options: {
responsive: true,
maintainAspectRatio: true,
scales: {
x: {
title: {
display: true,
text: 'Weight Percent (%)'
},
ticks: {
callback: function(value, index, ticks) {
// Show labels for every 5% interval if possible
if (index % 2 === 0) return this.getLabelForValue(value); // Label for every other point
return ";
}
}
},
y: {
title: {
display: true,
text: 'Molarity (mol/L)'
}
}
},
plugins: {
tooltip: {
callbacks: {
label: function(context) {
var label = context.dataset.label || ";
if (label) {
label += ': ';
}
if (context.parsed.y !== null) {
label += context.parsed.y.toFixed(3) + ' M';
}
return label;
}
}
}
}
}
};
}
function validateInput(inputId, errorId, minValue, maxValue) {
var input = document.getElementById(inputId);
var errorElement = document.getElementById(errorId);
var value = parseFloat(input.value);
var isValid = true;
errorElement.textContent = "";
errorElement.classList.remove("visible");
input.style.borderColor = "#ced4da"; // Default border color
if (isNaN(value)) {
errorElement.textContent = "Please enter a valid number.";
isValid = false;
} else if (input.value.trim() === "") {
errorElement.textContent = "This field cannot be empty.";
isValid = false;
} else if (value maxValue) {
errorElement.textContent = "Value cannot be greater than " + maxValue + ".";
isValid = false;
}
if (!isValid) {
input.style.borderColor = "red";
errorElement.classList.add("visible");
}
return isValid;
}
function calculateMolarity(wp = null, mm = null, rho = null) {
// Use provided values or get from inputs
var weightPercent = wp !== null ? wp : parseFloat(weightPercentInput.value);
var soluteMolarMass = mm !== null ? mm : parseFloat(soluteMolarMassInput.value);
var solutionDensity = rho !== null ? rho : parseFloat(solutionDensityInput.value);
// Perform validation if called from button click or if inputs are empty/invalid
var allValid = true;
if (wp === null) { // Only validate if not called internally for chart/table population
allValid = validateInput("weightPercent", "weightPercentError", 0, 100) && allValid;
allValid = validateInput("soluteMolarMass", "soluteMolarMassError", 0.01) && allValid;
allValid = validateInput("solutionDensity", "solutionDensityError", 0.001) && allValid;
}
if (!allValid && wp === null) { // Don't proceed if validation failed and not an internal call
molarityResult.textContent = "– M";
massSolute.textContent = "–";
massSolution.textContent = "–";
volumeSolution.textContent = "–";
return NaN; // Return NaN to indicate failure
}
// Use the formula: Molarity = (Weight Percent / 100) * Density (g/mL) / Molar Mass (g/mol) * 1000 (mL/L)
var massSoluteValue = (weightPercent / 100.0); // Assuming 100g of solution for easier calculation path
var molesSolute = massSoluteValue / soluteMolarMass;
var massSolutionValue = 100.0; // Base assumption for 100g solution
var volumeSolutionML = massSolutionValue / solutionDensity;
var volumeSolutionL = volumeSolutionML / 1000.0;
var molarity = molesSolute / volumeSolutionL;
// Update results display
molarityResult.textContent = isNaN(molarity) ? "– M" : molarity.toFixed(3) + " M";
massSolute.textContent = isNaN(massSoluteValue) ? "–" : massSoluteValue.toFixed(3) + " g";
massSolution.textContent = isNaN(massSolutionValue) ? "–" : massSolutionValue.toFixed(2) + " g";
volumeSolution.textContent = isNaN(volumeSolutionL) ? "–" : volumeSolutionL.toFixed(4) + " L";
// Update chart data if called without specific values (meaning from input changes)
if (wp === null) {
// We need to re-initialize or update the chart with current input values
// For simplicity, let's re-create the chart object if it exists, or create it
var currentWP = parseFloat(weightPercentInput.value);
var currentMM = parseFloat(soluteMolarMassInput.value);
var currentRho = parseFloat(solutionDensityInput.value);
if (molarityChart) {
molarityChart.destroy(); // Destroy previous chart instance
chartContext = null; // Reset context
}
if (!isNaN(currentWP) && !isNaN(currentMM) && !isNaN(currentRho) && currentWP >= 0 && currentMM > 0 && currentRho > 0) {
var config = getChartConfig(currentWP, currentMM, currentRho);
molarityChart = new Chart(chartContext = document.getElementById("molarityChart").getContext("2d"), config);
}
}
return molarity; // Return the calculated molarity
}
function populateTable() {
if (!tableBody) return;
tableBody.innerHTML = ""; // Clear existing rows
// Calculate molarity for each sample data point
sampleData.forEach(function(data) {
data.molarity = calculateMolarity(data.wp, data.mm, data.rho);
});
// Sort sampleData by Weight Percent for better readability
sampleData.sort(function(a, b) {
return a.wp – b.wp;
});
// Populate table
sampleData.forEach(function(data) {
var row = tableBody.insertRow();
var cellWP = row.insertCell(0);
var cellMM = row.insertCell(1);
var cellRho = row.insertCell(2);
var cellMolarity = row.insertCell(3);
cellWP.textContent = data.wp + "%";
cellMM.textContent = data.mm.toFixed(2) + " g/mol";
cellRho.textContent = data.rho.toFixed(2) + " g/mL";
cellMolarity.textContent = isNaN(data.molarity) ? "N/A" : data.molarity.toFixed(3) + " M";
});
}
function resetCalculator() {
weightPercentInput.value = "15";
soluteMolarMassInput.value = "58.44"; // NaCl molar mass
solutionDensityInput.value = "1.1"; // Approx density for 15% NaCl
// Clear errors
weightPercentError.textContent = "";
weightPercentError.classList.remove("visible");
soluteMolarMassError.textContent = "";
soluteMolarMassError.classList.remove("visible");
solutionDensityError.textContent = "";
solutionDensityError.classList.remove("visible");
weightPercentInput.style.borderColor = "#ced4da";
soluteMolarMassInput.style.borderColor = "#ced4da";
solutionDensityInput.style.borderColor = "#ced4da";
calculateMolarity(); // Recalculate with default values
}
function copyResults() {
var mainResult = molarityResult.textContent;
var massSoluteText = massSolute.textContent;
var massSolutionText = massSolution.textContent;
var volumeSolutionText = volumeSolution.textContent;
var formula = "Molarity (M) = (Weight Percent / 100) * Density (g/mL) / Molar Mass (g/mol) * 1000 (mL/L)";
var assumptions = "Key Assumptions:\n";
assumptions += "- Based on provided Weight Percent, Solute Molar Mass, and Solution Density.\n";
assumptions += "- Density is assumed constant regardless of temperature unless specified.\n";
assumptions += "- Calculations assume a pure solute.";
var textToCopy = "Molarity Calculation Results:\n\n";
textToCopy += "—————————–\n";
textToCopy += "Main Result: " + mainResult + "\n";
textToCopy += "—————————–\n\n";
textToCopy += "Intermediate Values:\n";
textToCopy += "- Mass of Solute: " + massSoluteText + "\n";
textToCopy += "- Mass of Solution (assumed 100g base): " + massSolutionText + "\n";
textToCopy += "- Volume of Solution: " + volumeSolutionText + "\n\n";
textToCopy += "Formula Used:\n" + formula + "\n\n";
textToCopy += assumptions;
navigator.clipboard.writeText(textToCopy).then(function() {
alert("Results copied to clipboard!");
}).catch(function(err) {
console.error('Failed to copy: ', err);
alert("Failed to copy results. Please copy manually.");
});
}
// Initial calculation and chart rendering on page load
document.addEventListener("DOMContentLoaded", function() {
resetCalculator(); // Set default values
populateTable();
// Need to ensure chart context is ready AFTER canvas element is available
var canvas = document.getElementById("molarityChart");
if (canvas) {
chartContext = canvas.getContext("2d");
var currentWP = parseFloat(weightPercentInput.value);
var currentMM = parseFloat(soluteMolarMassInput.value);
var currentRho = parseFloat(solutionDensityInput.value);
if (!isNaN(currentWP) && !isNaN(currentMM) && !isNaN(currentRho)) {
var config = getChartConfig(currentWP, currentMM, currentRho);
molarityChart = new Chart(chartContext, config);
}
}
});
// Add event listeners for real-time updates
weightPercentInput.addEventListener("input", function() { calculateMolarity(); });
soluteMolarMassInput.addEventListener("input", function() { calculateMolarity(); });
solutionDensityInput.addEventListener("input", function() { calculateMolarity(); });
// Function to update chart data dynamically (called by calculateMolarity)
// Note: calculateMolarity now handles chart updates internally.