Coal gasification can be represented by the equation: 2 C(s) + 2 H2O(g) → CH4(g) + CO2(g) ΔH = ? Use the following information to find ΔH for the reaction above. CO(g) + H2(g) → C(s) + H2O(g) ΔH = -131 kJ CO(g) + H2O(g) → CO2(g) + H2(g) ΔH = -41 kJ CO(g) + 3 H2(g) → CH4(g) + H2O(g) ΔH = -206 kJ

The for the reaction is 15 kJ.

Explanation:

Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.

According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.

The given chemical reaction follows:

The intermediate balanced chemical reaction are:

(1)       ( × 2)

(2)     

(3)     

The expression for enthalpy of the reaction follows:

Putting values in above equation, we get:

Hence, the for the reaction is 15 kJ.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.