2.1.5 - Redox Flashcards

Question

What is oxidation?

Answer 1

Oxidation is the process in which an element loses electrons, resulting in an increase in oxidation state.

Answer 2

Reduction is the process in which an element gains electrons, resulting in a decrease in oxidation state.

Answer 3

An oxidizing agent is a substance that gains electrons and is reduced in a redox reaction. It causes the oxidation of another substance.

Answer 4

A reducing agent is a substance that loses electrons and is oxidized in a redox reaction. It causes the reduction of another substance.

Answer 5

The oxidation state (or number) of an element is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic.

Answer 6

The oxidation state of an element in its pure form is 0.

Answer 7

The oxidation state of oxygen is typically -2, except in peroxides where it is -1.

Answer 8

The oxidation state of hydrogen is typically +1, except in metal hydrides where it is -1.

Answer 9

The oxidation state of alkali metals (Group 1) in compounds is always +1.

Answer 10

The oxidation state of halogens is typically -1, except when they are bonded to oxygen or fluorine, where they can have positive oxidation states.

Answer 11

The sum of the oxidation states of all atoms in a molecule or ion equals the charge on the molecule or ion. Use this rule, along with known oxidation states (e.g., hydrogen +1, oxygen -2), to determine the oxidation state of an unknown element.

Answer 12

The sum of the oxidation states of all atoms in a molecule or ion must equal the overall charge of the compound or ion.

Answer 13

A classic example of a redox reaction is the reaction between magnesium and oxygen to form magnesium oxide: 2Mg + O₂ → 2MgO Here, magnesium is oxidized (loses electrons) and oxygen is reduced (gains electrons).

Answer 14

A half-reaction shows either the oxidation or reduction process separately. For example: Oxidation half-reaction: Mg → Mg²⁺ + 2e⁻ Reduction half-reaction: O₂ + 4e⁻ → 2O²⁻

Answer 15

To balance a redox reaction in acidic solution: 1- Write the oxidation and reduction half-reactions. 2- Balance atoms other than hydrogen and oxygen. 3- Balance oxygen atoms by adding H₂O molecules. 4- Balance hydrogen atoms by adding H⁺ ions. 5- Balance the charges by adding electrons.

Answer 16

After balancing the redox reaction in acidic solution, add OH⁻ ions to both sides of the equation to neutralize H⁺ ions, creating water molecules if necessary, to balance the reaction in basic solution.

Answer 17

Disproportionation occurs when a substance is both oxidized and reduced in the same reaction. For example, in the reaction of chlorine with water: Cl₂ + H₂O → HCl + HClO

Answer 18

A half-cell is a part of a galvanic cell in which either oxidation or reduction occurs. It consists of a metal electrode in contact with a solution of its ions.

Answer 19

The electrochemical series is a list of elements or compounds ranked according to their ability to gain or lose electrons. The higher up the series, the stronger the oxidizing agent.

Answer 20

In a redox reaction, the substance higher in the electrochemical series will be reduced (gain electrons), and the substance lower in the series will be oxidized (lose electrons).

Answer 21

In redox reactions, electrons are transferred from the reducing agent (which loses electrons and is oxidized) to the oxidizing agent (which gains electrons and is reduced).

Answer 22

- The oxidizing agent is the substance that gains electrons (reduced). - The reducing agent is the substance that loses electrons (oxidized).

Answer 23

The oxidation number of chlorine in NaCl is -1, as it gains one electron to form the chloride ion (Cl⁻).

Answer 24

The oxidation number of oxygen in H₂O is -2, as oxygen typically has an oxidation state of -2 in most compounds.

2.1.5 - Redox Flashcards

(48 cards)