The initial rate of a chemical reaction is the instantaneous rate of reaction at time t=0. It is often determined experimentally by measuring the change in concentration of a reactant or product over a very short period at the beginning of the reaction. The initial rate is crucial for understanding reaction mechanisms and kinetics.
function calculateInitialRate() {
var initialConcentration = parseFloat(document.getElementById("initialReactantConcentration").value);
var finalConcentration = parseFloat(document.getElementById("finalReactantConcentration").value);
var time = parseFloat(document.getElementById("timeInterval").value);
var resultDiv = document.getElementById("result");
if (isNaN(initialConcentration) || isNaN(finalConcentration) || isNaN(time)) {
resultDiv.innerHTML = "Please enter valid numbers for all fields.";
return;
}
if (time <= 0) {
resultDiv.innerHTML = "Time interval must be greater than zero.";
return;
}
// The change in concentration is typically a decrease for reactants
var changeInConcentration = finalConcentration – initialConcentration;
// The rate is the absolute change in concentration over time.
// For reactants, the rate is often expressed as a positive value,
// so we take the absolute value of the change or consider it as rate of disappearance.
// Rate = |Δ[Reactant]| / Δt
var initialRate = Math.abs(changeInConcentration) / time;
resultDiv.innerHTML = "The calculated initial rate of reaction is: " + initialRate.toFixed(6) + " mol/(L·s)";
}
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