Oxidation and Chemical Formulas

Oxidation and Chemical Formulas

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Predicting Ion Charge

• Oxidation # - Charge that is typically formed.

• Find # of valence electrons (group #)

• Ask yourself if its easier to lose or gain electrons (if there are 4 or less, you lose electrons, 4 or more, you gain electrons.

• If you gain electrons – negative oxidation number (because you add negativity)

• if you lose electrons – positive oxidation number (you removed negative charges)

Multiple Choice

What would be the typical oxidation state of a Group 17 element?

• 1

• +2

• +1

• -1

Multiple Choice

What would be the typical oxidation state of a Group 2 element?

• -2

• +2

• +1

• -1

Multiple Choice

What would be the typical oxidation state of a Group 1 element?

• -2

• +2

• +1

• -1

Multiple Choice

What would be the typical oxidation state of a Group 16 element?

• -2

• +2

• +1

• -1

Keep in mind...

• Oxidation states on metals is almost always positive

• Oxidation states on nonmetals is almost always negative

• A Cation is an element that has LOST one or more outer electrons -is Oxidized

• An Anion is an element that has Gained one or more outer electrons -is Reduced

Multiple Choice

Aluminum is a Period 3, group 13 element. It is typically...

• Oxidized

• Reduced

Multiple Choice

Aluminum is a Period 3, group 13 element. It is typically...

• A Cation

• An Anion

• An Onion

• A Protion

Multiple Choice

Aluminum is a Period 3, group 13 element. It is typically...

• +1

• +2

• +3

• -3

Multiple Choice

Carbon is a Period 2, group 14 element. It is typically...

• Oxidized

• Reduced

Multiple Choice

Carbon is a Period 2, group 14 element. It is typically...

• A Cation

• An Anion

• An Onion

• A Protion

Multiple Choice

Carbon is a Period 2, group 14 element. It is typically...

• +3

• +4

• -3

• -4

Predicting a Chemical Formula

Oxidation can be used to predict Products using the Criss-Cross method.

Simplify the result as you would in math...

Remove any 1's (as shown in the image).

If all numbers are divisible, divide by the greatest common denominator (usually 2 or 3) to simplify.

Formula Order of the Elements

Why isn't Oxygen first in this formula?

Oxygen is the Anion.

Why put Lithium in front?

Lithium is the Cation.

When writing a Chemical formula, the Metal/Cation always goes first...Unless Carbon is involved.

Multiple Choice

Predict the resulting Chemical Formula:

Aluminum reacts with Carbon

• Al₃C₄

• Al₂C₃

• C₃Al₄

• C₄Al₃

Multiple Choice

Aluminum reacts with Carbon. Which was Reduced?

• Carbon

• Aluminum

Multiple Choice

Aluminum reacts with Carbon. Which was Oxidized?

• Carbon

• Aluminum

Multiple Choice

Predict the resulting Chemical Formula:

Magnesium reacts with Fluorine.

• MgF₂

• F₂Mg

• Mg₂F₁

• F₄Mg₂

Multiple Choice

Magnesium reacts with Fluorine. Which was Oxidized?

• Magnesium

• Fluorine

Multiple Choice

Magnesium reacts with Fluorine. Which was Reduced?

• Magnesium

• Fluorine

Multiple Choice

Predict the resulting Chemical Formula:

Nitrogen reacts with Calcium.

• CaN₂

• Ca₂N₃

• Ca₃N₂

• N₂Ca₃

Multiple Choice

Nitrogen reacts with Calcium. Which was Reduced?

• Calcium

• Nitrogen

• the calcium nitride

• Nothing, mass is the same

Multiple Choice

Nitrogen reacts with Calcium. Which was Oxidized?

• Calcium

• Nitrogen

• the calcium nitride

• Nothing, mass is the same

The Product is the result of the Chemical Reaction.

In a generic Synthesis Reaction, the Product is a single molecule that is heavier than than the reactants. The mass of the new molecule consists of the combined atomic masses of each atom in the Chemical Formula.

Multiple Choice

Aluminum reacts with Carbon. What is the Molecular Mass of the Product?

• 89.997

• 143.96

• 87.474

• 94.957

Multiple Choice

Magnesium reacts with Fluorine. What is the Molecular Mass of the Product?

• 28.308

• 37.996

• 43.303

• 62.301

Multiple Choice

Nitrogen reacts with Calcium. What is the Molecular Mass of the Product?

• 54.085

• 80.156

• 120.234

• 148.248

Multiple Choice

Sulfur reacts with Sodium. What is the Molecular Mass of the Product?

• 22.990

• 32.06

• 45.98

• 78.04

Multiple Choice

Nitrogen reacts with Oxygen. What is the Molecular Mass of the Product?

• 46.0

• 64.2

• 76.01

• 80.043