<u>Answer:</u> For the given equation, only iron has the value of 
equal to 0 kJ.
<u>Explanation:</u>
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:
![\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f(product)]-\sum [n\times \Delta H^o_f(reactant)]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f%28product%29%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f%28reactant%29%5D)
For the given chemical reaction:
The equation for the enthalpy change of the above reaction is:
![\Delta H^o_{rxn}=[(1\times \Delta H^o_f_{(Fe(s))})+(3\times \Delta H^o_f_{(CO_2(g))})]-[(3\times \Delta H^o_f_{(CO(g))})+(2\times \Delta H^o_f_{(Fe_2O_3(s))})]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%281%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28Fe%28s%29%29%7D%29%2B%283%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28CO_2%28g%29%29%7D%29%5D-%5B%283%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28CO%28g%29%29%7D%29%2B%282%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28Fe_2O_3%28s%29%29%7D%29%5D)
The enthalpy of formation for the substances present in their elemental state is taken as 0.
Here, iron is present in its elemental state which is solid.
Hence, for the given equation, only iron has the value of equal to 0 kJ.
Answer:
D. only 2 and 3
Explanation:
The Grignard compound or reagent is a highly reactive compound formed from the reaction between an ether solvent containing magnesium and a haloalkane. This compound can also be used to create a C-C bond (carbon-carbon). Based on the properties and structure of a Grignard compound, the answer is option D.
C7H14 + 10.5 O2 -> 7 CO2 + 7 H2O
Or, if whole numbers must be used:
2 C7H14 + 21 O2 -> 14 CO2 + 7 H2O
Explanation:
Oceans can influence weather and climate. For example, cities located near large water bodies like oceans tend not to have extreme climates
the alkaline eart metal s are
Beryllium
Magnesium
calcium
Strontium
barium
out of these Magnesium reacts with oxygen and produces bright light due to formation of MgO
all other metals also form oxides but the oxide of Mg is brightest
