The right answer is the first molecule (3-methyl-butan-2-one).
There are many bands around 2900-3000 cm-1 proving the presence de C-H bound.
There an intense band in 1700 cm-1 proving the presence of C=O.
There's no band proving the presence of aromatic structure, C=C bond nor C-N bond.
From the conservation of mass, matter is not created nor
destroyed. So ponder it this way, for example I put one piece of toast in a
toaster, but when it is done I had two pieces, that makes no sense right? Same
thing with a chemical reaction but in molecular terms, all things must stay constant.
If you put a convinced amount you have to get that quantity back, not less or
not more in broad terms.
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
Answer:
Which one? 1, 2, 3, 4 ,5, 6, or 7?
Explanation:
Answer:
1) Electron
Explanation:
It carries a negative charge of 1.602176634 × 10−19 coulomb, which is considered the basic unit of electric charge. The rest mass of the electron is 9.1093837015 × 10−31 kg, which is only 1/1,836the mass of a proton.