Question

Fe^3+ (aq) + SCN^-(aq) ======FeSCN^2+ (aq)

In which the FeSCN^2+ species is a deep red colored complex. Write a procedure you could do in this experiment to determine whether deltaH for this reaction is either positive or negative.

Answer 1

During any chemical reaction, heat can be either taken in from the environment or released out into it. The heat exchange between a chemical reaction and its environment is known as the enthalpy of reaction, or H. However, H can't be measured directly — instead, scientists use thechange in the temperature of a reaction over time time to find the change in enthalpy over time (denoted as ∆H). With ∆H, a scientist can determine whether a reaction gives off heat (or "isexothermic") or takes in heat (or "is endothermic"). In general, ∆H = m x s x ∆T, where m is the mass of the reactants, s is the specific heat of the product, and ∆T is the change in temperature from the reaction.

For this reaction equimolar mixture of [Fe³⁺] and [SCN^-] solution is mixed at a fixed temperature. The change in temperature is calculated using a thermometer and from that data Enthalpy change is calculated.