Balance the following reaction and use the equation to calculate the δhrxn. c3h8(g) + o2(g) → co2(g) + h2o(g) round your answer to the nearest whole number. δhrxn=kj/mole

The reaction corresponds to the combustion of propane (C3H8). The balanced reaction is:

C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g)

The reaction enthalpy is given as:

ΔHrxn = ∑nΔH°f(products) - ∑ nΔH°f(reactants)

          = [3ΔH°f(CO2(g)) + 4ΔH°f(H2O(g)] - [1ΔH°f(C3H8(g)) + 5ΔH°f(O2(g)]

          = [3(-393.5) + 4(-241.8)] - [-103.9 + 5(0)] = -2043.8 kJ

The enthalpy for the combustion of propane is -2044 kJ

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.