Calculate the Value of Rate Constant
function calculateRateConstant() {
var a = parseFloat(document.getElementById('preExpA').value);
var ea_kj = parseFloat(document.getElementById('actEnergy').value);
var t = parseFloat(document.getElementById('tempK').value);
var r = 8.314;
var error = false;
if (isNaN(a) || a <= 0) {
alert("Please enter a valid positive Pre-exponential Factor (A).");
error = true;
} else if (isNaN(ea_kj)) {
alert("Please enter a valid Activation Energy (Ea).");
error = true;
} else if (isNaN(t) || t <= 0) {
alert("Please enter a valid Temperature in Kelvin (must be greater than 0).");
error = true;
}
if (!error) {
// Convert Ea from kJ/mol to J/mol
var ea_j = ea_kj * 1000;
// Arrhenius calculation: k = A * exp(-Ea / (R * T))
var exponent = -ea_j / (r * t);
var k = a * Math.exp(exponent);
// Result formatting
var displayK = k;
if (k 10000) {
displayK = k.toExponential(4);
} else {
displayK = k.toFixed(6);
}
document.getElementById('kValueDisplay').innerText = displayK;
document.getElementById('kFormulaDisplay').innerText = "Calculation: " + a + " * e^(-" + ea_j + " / (8.314 * " + t + "))";
document.getElementById('kResultContainer').style.display = 'block';
// Scroll to result
document.getElementById('kResultContainer').scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}
}