Ionic Charges and Dissociation Concepts

This lecture covers the dissociation of ionic compounds in water, focusing on how to predict the ions formed and write balanced dissociation equations. It provides guidelines for writing these equations, emphasizing the importance of understanding ion charges and using the periodic and solubility charts. The lecture includes examples of dissociation for various compounds, such as potassium phosphate, silver nitrate, acetate, ammonium, and sulfate compounds, highlighting the role of transition elements and their variable oxidation states. The session concludes with a reference to additional resources.

What is the primary guideline for writing dissociation equations?

• Write the ions without charges.

• Ignore the Periodic Chart.

• Use the solubility chart for all ions.

• Write the ions and their charges if possible.

When K3PO4 dissociates in water, what is the charge on the phosphate ion?

• +2

• +3

• -3

• -2

Which of the following is a polyatomic ion with a -1 charge?

• Sulfate

• Carbonate

• Nitrate

• Phosphate

What is the charge on the ammonium ion (NH4)?

• +1

• -1

• +2

• -2

How does the subscript affect the dissociation of a compound like K2SO4?

• It is ignored.

• It is moved in front of the ion.

• It is subtracted from the charge.

• It is added to the charge.

What is the charge on cesium in Cs2CO3?

• +1

• -1

• +2

• -2

Which group does calcium belong to, and what is its typical charge?

• Group 1, +1

• Group 2, +2

• Group 3, +3

• Group 4, +4

What is the oxidation state of copper in copper sulfate if sulfate has a -2 charge?

• +4

• +1

• +2

• +3

How do you determine the charge of a transition element like chromium in chromium bromide?

• By assuming it is always +3.

• By using the solubility chart.

• By checking the charge of the attached ion.

• By assuming it is always +2.

In titanium sulfate, what is the total positive charge if the sulfate has a -6 total negative charge?

• +3

• +4

• +6

• +2