Question

What substance is oxidized in the reaction mgo cu2 → mg2 cuo? cu cu2 mg mg2

Answer 1

In the given reaction, magnesium (Mg) is oxidized as it goes from an oxidation number of 0 to +2, while copper (Cu) is the element that gets reduced going from +2 to 0.

Step-by-step explanation:

In the chemical reaction Mg(s) + Cu(NO3)2(aq) → Mg(NO3)2(aq) + Cu(s), we are asked to identify what substance is oxidized. Oxidation involves the loss of electrons by a substance. In this metal replacement reaction, magnesium (Mg) starts in its elemental form with an oxidation number of 0 and ends up in a compound, magnesium nitrate, where it has an oxidation number of +2. This increase in oxidation number indicates that magnesium is the element that gets oxidized.

Using oxidation numbers, we can also determine what is reduced. Copper (Cu) is reduced as it goes from an oxidation state of +2 in copper(II) nitrate to 0 in its elemental form. Therefore, in this reaction, Mg is oxidized and Cu is reduced following the oil rig mnemonic: 'oxidation is loss, the reduction is gain'.

Answer 2

In the reaction MgO + Cu, Mg (magnesium) is the substance that is oxidized as it goes from being part of a compound to a cation, losing two electrons in the process.

Step-by-step explanation:

In the reaction MgO + Cu, the substance that is oxidized is Mg (magnesium). Oxidation is defined as the loss of electrons or an increase in oxidation state by a molecule, atom, or ion. When MgO reacts with Cu, magnesium is oxidized from an oxidation state of +2 (in MgO) to +2 (in Mg2+), but because it is going from a compound to a cation, it is considered to be oxidized in this context. The elemental form of magnesium (Mg) has an oxidation state of 0, so when it forms Mg2+, it loses two electrons (oxidation). Meanwhile, Cu goes from Cu (with an oxidation state of 0) to Cu2+ after it gains two electrons (reduction), forming CuO. Hence, the magnesium in MgO is the component that gets oxidized in this reaction.