Writing Formulas for Ionic Compounds with Polyatomic Ions

The video tutorial explains how to write chemical formulas for compounds containing polyatomic ions. It covers the use of the periodic table and common ion tables to identify elements and their charges. The tutorial demonstrates the process with examples like potassium nitrate, sodium phosphate, calcium phosphite, magnesium phosphate, and ammonium carbonate. It emphasizes balancing charges and using methods like the criss-cross technique to ensure correct formulas. The video also highlights the importance of understanding polyatomic ions as single units and suggests memorizing common ions for efficiency.

What is the charge of potassium (K) in the periodic table?

• -2

• -1

• +2

• +1

Which of the following is a polyatomic ion?

• K

• Cl

• Na

• NO3-

What is the correct formula for potassium nitrate?

• K(NO3)2

• KNO2

• KNO3

• K2NO3

What is the charge of sodium (Na) in the periodic table?

• +2

• -2

• +1

• -1

What is the formula for sodium phosphate?

• NaPO4

• Na2PO4

• Na3PO4

• Na4PO4

What is the charge of calcium (Ca) in the periodic table?

• -2

• -1

• +2

• +1

What is the correct formula for calcium phosphite?

• CaPO3

• Ca2(PO3)3

• Ca3(PO3)2

• Ca(PO3)2

What is the charge of magnesium (Mg) in the periodic table?

• -2

• -1

• +2

• +1

What is the formula for magnesium phosphate?

• Mg3(PO4)2

• Mg(PO4)3

• Mg2(PO4)3

• Mg(PO4)2

What is the correct formula for ammonium carbonate?

• NH4(CO3)2

• NH4CO3

• (NH4)2CO3

• (NH4)2(CO3)2