Which statement is a correctly written thermochemical equation?

2C8H18 + 25O2 →16CO2 + 18H2O , ΔH = −5,471 kJ/mol

4Fe (s) + 3O2 (g)→2Fe2O3 (s) , ΔH = −3,926 kJ

NH4Cl → NH4+ + Cl–

C3H8 (g) + O2(g)→CO2 (g) + H2O (l) , ΔH = −2,220 kJ/mol

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.