Zn(s)+2H+(aq)->Zn2+(aq)+H2(g)
Br2(aq)+2I-(aq)->2Br-(aq)+I2(aq)
Name one compound containing H+ ions and another containing I- ions, which would be suitable for these reactions.
Ezplain why zinc is said to be oxidised in its reaction.
Complete the half equation to show the oxidising action of bromine.
_I- ->I2+____
HCl would be suitabl as a source for H^+.
KI would work as a cation for I^-.
Zn is oxidized because it goes from an oxidation state of zero to one of +2. That is a loss of electrons (2 per atom of Zn) and oxidation is defined as the loss of electrons.
2I^- ==> I2 + 2e
Notice this is a loss of electrons, too, and that is why iodide ion is oxidized.
To find one compound containing H+ ions and another containing I- ions suitable for the given reactions, we need to look for compounds with these ions.
1. A suitable compound containing H+ ions is hydrochloric acid (HCl). In an aqueous solution, it dissociates into H+ and Cl- ions. So, HCl(aq) would be a suitable compound as a source of H+ ions.
2. A suitable compound containing I- ions is potassium iodide (KI). When dissolved in water, it dissociates into K+ and I- ions. Thus, KI(aq) would be a suitable compound as a source of I- ions.
Now, let's move on to why zinc is said to be oxidized in its reaction.
In the given equation: Zn(s) + 2H+(aq) -> Zn2+(aq) + H2(g)
Zinc starts as a neutral solid (Zn). After the reaction, it forms a positively charged ion (Zn2+). This increase in oxidation state, from zero to +2, indicates that zinc has lost electrons and undergone oxidation.
Zinc loses two electrons and is oxidized from its elemental form (Zn) to form Zn2+ ions. Since oxidation involves the loss of electrons, zinc is said to be oxidized in this reaction.
Lastly, let's complete the half equation to show the oxidizing action of bromine.
The half equation can be written as:
I- -> I2 + 2e-
This represents the reduction of iodide ions (I-) to form iodine molecules (I2) by gaining two electrons (2e-). Bromine acts as the oxidizing agent, causing the iodide ions to lose electrons and transforming into iodine.
Note: The "Oxidizing action" refers to the ability of an element or compound to oxidize (i.e., cause another species to lose electrons) during a chemical reaction.