We are given.... #Ca(s) + 1/2 O_2(g) -> CaO(s)# #;DeltaH_1^@ = -635.1*kJ*mol^-1# #CaCO_3(s) rarr CaO(s) + CO_2(g)# #;DeltaH_2^@ = 178.3 *kJ*mol^-1# What is the enthalpy of reaction for #Ca(s)+1/2O_2(g) +CO_2(g) rarr CaCO_3(s)#?
1 Answer
Explanation:
We want
We are given....
And if take the former reaction, and add it the REVERSE of the latter reaction we get....
And we cancel out common reagents....
..to give....
And this is precisely the reaction whose enthalpy we wish to estimate...
And so we simply sum the GIVEN enthapies together and boserve the sign conventions .............