Metal & Acid Reactions as Redox Reactions Flashcards

All 6 cards in this deck

What do oxidation and reduction mean in terms of electrons?

Oxidation is loss of electrons; reduction is gain of electrons (OIL RIG).

In $\mathrm{Mg + 2HCl \rightarrow MgCl_2 + H_2}$, which species is oxidised?

Magnesium — it loses 2 electrons to form $\mathrm{Mg^{2+}}$.

In $\mathrm{Mg + 2HCl \rightarrow MgCl_2 + H_2}$, which species is reduced?

The hydrogen ions ($\mathrm{H^+}$) — each gains an electron to form $\mathrm{H_2}$.

Write the half equation for the oxidation of magnesium when it reacts with an acid.

$\mathrm{Mg \rightarrow Mg^{2+} + 2e^-}$

Write the half equation for the reduction of hydrogen ions in a metal–acid reaction.

$\mathrm{2H^+ + 2e^- \rightarrow H_2}$

True or false? When iron reacts with hydrochloric acid, the iron is reduced.

False. Iron is oxidised (it loses electrons); the hydrogen ions are reduced.