Chemical Formulas and Ions

The video tutorial explains how to write the chemical formula for aluminum nitrite. It begins by identifying aluminum and nitrite, noting that nitrite is a polyatomic ion. The tutorial discusses the charges of aluminum (3+) and nitrite (1-) and uses the crisscross method to balance these charges, resulting in the formula Al(NO2)3. The video concludes by verifying the formula to ensure a net charge of zero.

What is the chemical symbol for aluminum?

• Am

• Au

• Ag

• Al

Which of the following is a polyatomic ion?

• Aluminum

• Nitrite

• Oxygen

• Hydrogen

What is the charge of the aluminum ion?

• 2+

• 1+

• 3+

• 4+

What is the charge of the nitrite ion?

• 4-

• 2-

• 1-

• 3-

Why do we need to balance the charges when writing a chemical formula?

• To make the compound look nice

• To ensure the compound is stable

• To make the compound colorful

• To ensure the compound is reactive

What method is used to balance the charges in aluminum nitrite?

• Crisscross method

• Substitution method

• Addition method

• Cross-multiplication method

Why do we use parentheses around the nitrite ion in the formula?

• To indicate it is a polyatomic ion

• To make it look symmetrical

• To separate it from aluminum

• To highlight its color

What is the net charge of a correctly written chemical formula?

• Positive

• Variable

• Negative

• Zero

What is the final formula for aluminum nitrite?

• Al(NO2)3

• Al3(NO2)

• AlNO2

• AlN3O2

Who is the presenter of the video?

• Dr. A

• Dr. B

• Dr. C

• Dr. D