which equation is a correctly written thermochemical equation? o 2c8h18 + 25o2 → 16co2 + 18h2o…

which equation is a correctly written thermochemical equation? o 2c8h18 + 25o2 → 16co2 + 18h2o, δh=-5,471kj/mol o fe(s)+o2(g) → fe2o3(s), δh=-3,926kj o c3h8(g)+5o2(g) → 3co2(g) + 4h2o(l), δh=-2,220kj/mol o nh4cl → nh4+ + cl-

which equation is a correctly written thermochemical equation? o 2c8h18 + 25o2 → 16co2 + 18h2o, δh=-5,471kj/mol o fe(s)+o2(g) → fe2o3(s), δh=-3,926kj o c3h8(g)+5o2(g) → 3co2(g) + 4h2o(l), δh=-2,220kj/mol o nh4cl → nh4+ + cl-

Answer

Explanation:

Step1: Check stoichiometry and state - symbols

A thermochemical equation must have balanced stoichiometry and proper state - symbols (s for solid, l for liquid, g for gas, aq for aqueous). Also, the enthalpy change ($\Delta H$) should be correctly associated with the reaction. The first equation $2C_8H_{18}+25O_2\rightarrow16CO_2 + 18H_2O,\Delta H=- 5471kJ/mol$ has no state - symbols for $C_8H_{18}$. The second equation $Fe(s)+O_2(g)\rightarrow Fe_2O_3(s),\Delta H=-3926kJ$ is not balanced (the oxygen atoms are not balanced: 2 on the left and 3 on the right). The fourth equation $NH_4Cl\rightarrow NH_4^++Cl^-$ is an ionization equation and not a thermochemical equation for a chemical reaction with heat change in the traditional sense. The third equation $C_3H_8(g)+5O_2(g)\rightarrow3CO_2(g)+4H_2O(l),\Delta H = - 2220kJ/mol$ has balanced stoichiometry ($3$ C, $8$ H, and $10$ O on both sides), proper state - symbols for all reactants and products, and a correctly written enthalpy change for the reaction.

Answer:

C. $C_3H_8(g)+5O_2(g)\rightarrow3CO_2(g)+4H_2O(l),\Delta H=-2220kJ/mol$