Complete and balance this decomposition reaction
HI ==>
is this reaction
HI ==> H + I ?
or... HI ==> H2 + I2 ?
why?
Remember that H and I are diatomic. The diatomic gases are H2, N2, O2, F2, Br2, Cl2, I2 along with their cousins P4 and S8. Look at the periodic chart and find them. You can remember what they are by WHERE they are in relation to each other. H is the only one "out of pocket" but the others form a nice block.
The balanced decomposition reaction for HI can be represented as:
2 HI ⟶ H2 + I2
In this reaction, one molecule of hydrogen iodide (HI) decomposes to form one molecule of hydrogen gas (H2) and one molecule of iodine gas (I2).
The reason for this balanced equation is the conservation of atoms. We need two iodine atoms on the product side since the original compound, HI, consists of two iodine atoms. Similarly, we need two hydrogen atoms on the product side to match the two hydrogen atoms in HI. Therefore, the balanced equation is HI ⟶ H2 + I2.
To determine the balanced decomposition reaction for HI (hydrogen iodide), we need to consider the oxidation states of the elements involved.
In the first option: HI ==> H + I
In this scenario, hydrogen (H) would have an oxidation state of +1, and iodine (I) would have an oxidation state of -1. However, both elements would prefer more stable oxidation states. Hydrogen usually forms H2, and iodine usually forms I2, rather than existing as single atoms.
In the second option: HI ==> H2 + I2
In this case, hydrogen would have an oxidation state of zero in H2, and iodine would have an oxidation state of zero in I2. These oxidation states are more stable for both elements.
Therefore, the balanced decomposition reaction for HI is as follows:
2HI ==> H2 + I2
This reaction ensures that the overall charge and mass are balanced and reflects the preferred oxidation states of hydrogen and iodine.