recognizing enthalpy of formation\nwhich substances have δhf = 0 kj/mol by definition? choose four correct…
recognizing enthalpy of formation\nwhich substances have δhf = 0 kj/mol by definition? choose four correct answers.\nbr₂(l)\no₂(g)\nh₂o(l)\nhe(g)\nn(g)\nfe(s)
Answer
Brief Explanations:
The standard enthalpy of formation ($\Delta H_f$) of an element in its standard state is zero. The standard state of bromine is $Br_2(l)$, oxygen is $O_2(g)$, helium is $He(g)$ and iron is $Fe(s)$. Water ($H_2O(l)$) is a compound and not an element in its standard - state, and $N(g)$ is not the standard state of nitrogen (the standard state of nitrogen is $N_2(g)$).
Answer:
$Br_2(l)$, $O_2(g)$, $He(g)$, $Fe(s)$