Question

Which reaction can be used to calculate the enthalpy of formation of a substance

Answer 1

option B

Step-by-step explanation

Firstly, we will need to define the standard heat of formation

The standard heat of formation is the amount of heat evolved or absorbed when one mole of a compound is completely formed from its constituent elements under standard conditions.

From the options provided, you will see that only option B aligns with the definition of the standard heat of formation.

`\text{ H}_(2(g))+\text{ }(1)/(2)O_2\rightarrow\text{ H}_2O(l)`

From the above reaction, you will see that 1 mole of water is formed from hydrogen and oxygen.

Hence, the answer is option B