Mastering Charge Calculation for Polyatomic Ions

This video tutorial teaches two tricks to find the charge on polyatomic ions. The first trick, widely known, applies to ions with two types of atoms, using group numbers to determine charge. The second, a personal trick, is for ions with three types of atoms, combining known charges of components. Examples include sulfate, nitrate, chlorate, and more. Exceptions like phosphate are noted. The tutorial emphasizes understanding group numbers and applying rules to determine charges effectively.

What is the group number of hydrogen in the periodic table?

• 2a

• 1a

• 4a

• 3a

According to the famous trick, what is the charge on a polyatomic ion if both group numbers are even?

• Positive 2

• Positive 1

• Negative 2

• Negative 1

What is the charge on a nitrate ion according to the famous trick?

• Positive 2

• Negative 1

• Negative 2

• Positive 1

Which of the following ions has a charge of negative 2?

• Chromate

• Ammonium

• Cyanide

• Permanganate

What is the charge on an ammonium ion?

• Negative 1

• Negative 2

• Positive 1

• Positive 2

Which ions are exceptions to the famous trick and have a charge of negative 3?

• Phosphate and Phosphite

• Sulfate and Sulfite

• Nitrate and Nitrite

• Chlorate and Chlorite

In the personal trick, what is the charge on hydrogen sulfate?

• Positive 2

• Negative 1

• Negative 2

• Positive 1

What is the charge on dihydrogen phosphate according to the personal trick?

• Negative 1

• Positive 2

• Negative 2

• Positive 1

How many types of atoms are considered in the personal trick for polyatomic ions?

• One

• Two

• Four

• Three

What is the charge on hydrogen carbonate according to the personal trick?

• Positive 2

• Positive 1

• Negative 2

• Negative 1