This page estimates the required volume for a Continuous Stirred-Tank Reactor (CSTR). For a simple first-order reaction, the volume (V) is calculated using the formula: V = F₀ * X / (-rₐ), where F₀ is the molar flow rate (or volumetric flow rate v₀ if concentration Cₐ₀ is constant), X is the conversion, and -rₐ is the rate of reaction. For a first-order reaction (-rₐ = k * Cₐ = k * Cₐ₀ * (1 - X)), the formula simplifies to V = v₀ * X / (k * (1 - X)). Space time (τ = V / v₀) is calculated, which equals the mean residence time for an ideal CSTR.