Calculate the standard enthalpy change for the reaction 2A+B⇌2C+2D Use the following data: Substance ΔH∘f (kJ/mol) A -235 B -413 C 193 D -493

ΔH = 283kJ/mol

Explanation:

Using Hess's law, the ΔH of a reaction is equal to the sum of ΔH° of products times its coefficient subtracting the sum of ΔH° of reactants times its coefficient. Replacing, for the reaction:

ΔH = 2ΔH°C + 2ΔH°D - (2ΔH°A+ΔH°B)

ΔH = 2*193kJ/mol + 2*-493kJ/mol - (2*-235kJ/mol+ (-413kJ/mol)

answer; protein;

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.