To calculate the activation energy Ea for the reaction, we can use the Arrhenius equation:k = Ae^-Ea/RT Where:k = rate constant 5.62 x 10^-4 s^-1 A = pre-exponential factor also known as the frequency factor Ea = activation energy which we want to find R = gas constant 8.314 J/molK T = temperature 298 K First, we need to find the pre-exponential factor A . To do this, we can use the overall order of the reaction n and the rate constant k :A = kT^nSince the overall order of the reaction is 2:A = 5.62 x 10^-4 s^-1 298 K ^2A 5.00 x 10^5 s^-1Now that we have the pre-exponential factor, we can rearrange the Arrhenius equation to solve for the activation energy Ea :Ea = -RT ln k/A Ea = - 8.314 J/molK 298 K ln 5.62 x 10^-4 s^-1 / 5.00 x 10^5 s^-1 Ea 1.88 x 10^5 J/molThe activation energy required for the chemical reaction between hydrogen gas and oxygen gas to form water is approximately 1.88 x 10^5 J/mol.