Consider the following equation: sio2 (s) + 3c (graphite) --> sic (s) + 2co (g) δh rxn = 624.6 kj / mol rxn. using the following standard enthalpy of formation data, calculate standard enthalpy of formation for sic (s). a. standard enthalpy of formation sio2 (s) = -910.9 kj/mol b. standard enthalpy of formation co (g) = -110.5 kj/mol

The enthalpy of the formation of is coming out to be -65.3 kJ/mol

Explanation:

Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as

The equation used to calculate enthalpy change is of a reaction is:  

For the given chemical reaction:

The equation for the enthalpy change of the above reaction is:

We are given:

Putting values in above equation, we get:

Hence, the enthalpy of the formation of is coming out to be -65.3 kJ/mol.

passing a magnet thought the

mixture , because iron gets attracted to magnet .

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.