Oxygen Reactions

Strong Oxidizing Agent

Elemental oxygen (O₂) is classified as a strong __________ because it reacts with most other elements and many compounds.

Most Elements and Many Compounds

Elemental oxygen reacts with what broad categories of substances?

Oxidizing Agent

In a redox reaction, the substance that causes another substance to become oxidized while itself being reduced is called an __________.

Accepts Electrons

What does oxygen generally do with electrons when it functions as an oxidizing agent?

Noble Gases, Halogens, and a Few Low-Reactivity Transition Metals

Name the major groups of elements that generally do NOT react directly with elemental oxygen under the conditions discussed in the lesson.

Noble Gases

Which major family of elements generally does not react directly with oxygen?

Halogens

Which reactive nonmetal family nevertheless does not react directly with elemental oxygen to form its oxygen compounds?

Low-Reactivity Transition Metals

A few second- and third-row __________ with high reduction potentials do not react directly with oxygen.

Higher Reduction Potentials than Copper

The low-reactivity metals that do not readily react directly with oxygen are described in the lesson as having __________.

Rust

The familiar product resulting from the reaction of iron with oxygen is commonly called ______.

Oxidation of Iron

Rusting is an everyday example of what general type of reaction involving oxygen?

Room Temperature or Elevated Temperatures

Depending on the element, direct reaction with oxygen may occur at __________ or at __________.

Oxides

Less-active metals and nonmetals generally react with oxygen to form ______.

Peroxides or Superoxides

More-active metals may react with oxygen to form __________ rather than ordinary oxides.

Magnesium Oxide (MgO)

What oxide is produced when magnesium reacts with oxygen?

2Mg(s) + O₂(g) → 2MgO(s)

Chemical equation for the direct reaction of magnesium with oxygen.

Phosphorus(V) Oxide (P₄O₁₀)

What product is formed in the reaction P₄ + 5O₂ → ______?

P₄(s) + 5O₂(g) → P₄O₁₀(s)

Chemical equation showing the direct reaction of phosphorus with oxygen given in the lesson.

Metal + Oxygen → Metal Oxide

What general reaction pattern is demonstrated by the formation of MgO from Mg and O₂?

Nonmetal + Oxygen → Nonmetal Oxide

What general reaction pattern is demonstrated by the formation of P₄O₁₀ from phosphorus and O₂?

Further Oxidation

A compound containing an element that has not reached its maximum oxidation state may sometimes undergo __________ when exposed to oxygen.

Oxidation State

Whether an element within a compound can undergo further oxidation can often be predicted by examining its __________.

Lower than its Maximum Oxidation State

If an element in a compound is at an oxidation state __________, further oxidation by O₂ may be possible.

Carbon Monoxide (CO)

This carbon oxide can undergo further oxidation because carbon has not yet reached its highest common oxidation state.

Carbon Dioxide (CO₂)

Carbon monoxide can be further oxidized by oxygen to produce ______.

2CO(g) + O₂(g) → 2CO₂(g)

A representative equation showing further oxidation of carbon monoxide.

P₄O₆

This phosphorus oxide can undergo further oxidation by oxygen to form P₄O₁₀.

P₄O₁₀

Further oxidation of P₄O₆ produces ______.

Hydrogen Sulfide (H₂S)

This compound contains sulfur in the −2 oxidation state and can therefore undergo further oxidation by oxygen.

−2

What is the oxidation state of sulfur in H₂S?

Because sulfur in H₂S is not at its maximum oxidation state.

Why can H₂S undergo further oxidation by elemental oxygen?

Water and Sulfur Dioxide

What products are formed when H₂S reacts with sufficient oxygen according to the reaction in the lesson?

2H₂S(g) + 3O₂(g) → 2H₂O(l) + 2SO₂(g)

Chemical equation for the oxidation of hydrogen sulfide by oxygen given in the lesson.

Sulfur Dioxide (SO₂)

In the oxidation of H₂S by O₂ shown in the lesson, sulfur is oxidized to this sulfur oxide.

Oxidation

The loss of electrons or an increase in oxidation state is called __________.

Reduction

The gain of electrons or a decrease in oxidation state is called __________.

Oxygen is Reduced

When elemental O₂ acts as an oxidizing agent and accepts electrons, is the oxygen oxidized or reduced?

The Other Substance is Oxidized

If O₂ functions as the oxidizing agent in a reaction, what happens to the substance that transfers electrons to oxygen?

Oxidation-Reduction (Redox) Reaction

A reaction involving simultaneous oxidation and reduction is called a __________.

Fluorine

Only this extremely reactive element can readily oxidize oxygen in most oxides under the chemistry discussed in the lesson.

Because fluorine is extremely reactive and more electronegative than oxygen.

Why is fluorine exceptional in its ability to oxidize oxygen in compounds?

Difficulty of Removing Electrons from Oxygen

The ease with which elemental oxygen accepts electrons is mirrored by the __________ once oxygen is present in most oxides.

Oxide Formation

A very common result when oxygen reacts with an element is the formation of an ______.

Direct Combination with Oxygen

Producing an oxide by reacting an element directly with O₂ is an example of __________.

Not All Oxides Form by Direct Reaction

True or False concept: Every oxide can be prepared simply by reacting its element directly with O₂. If false, state the correct idea.

False — some oxides cannot be formed conveniently by direct reaction with elemental oxygen.

Every oxide can be prepared simply by reacting its element directly with O₂. True or false?

Oxidation State Analysis

What useful method can help predict whether oxygen can further oxidize an element already present inside a compound?