Answer : The enthalpy change for the reaction is, 419.5 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
The given chemical reaction is,

Now we have to determine the enthalpy change for the reaction below:

By reversing and then dividing the reaction by 2, we get the enthalpy change for the reaction.
The expression will be:



Therefore, the enthalpy change for the reaction is, 419.5 kJ
A wave is a disturbance that carries energy from one place to another. Matter is NOT carried with the wave! A wave can move through matter (a medium). If it must have a medium, it is called a mechanical wave.
Answer:
The vertical columns of the periodic table are called groups, or families. The significance is elements with similar properties are placed in the same vertical columns. The horizontal rows of the periodic table are called periods. The significance is that properties vary from left to right along the rows.
Explanation:
We just did this in science
Answer:
Option a → 4 mol NH₃
Explanation:
This the unbalanced reaction
NH₃ + O₂ ⟶ N₂ + H₂O
The balanced reaction:
4NH₃ + 3O₂ → 2N₂ + 6H₂O
4 mol of ammonia
3 mol of oxygen
2 mol of nitrogen
6 mol of water