Calcium Cyanide and Ionic Charges

The video tutorial explains how to write the formula for calcium cyanide. It begins by identifying the element symbol for calcium and the polyatomic ion cyanide, which is not found on the periodic table. The tutorial discusses the ionic charges of calcium and cyanide, emphasizing the need for the charges to balance to achieve a neutral compound. The final formula for calcium cyanide is presented as Ca(CN)2, indicating two cyanide ions are needed to balance the charge of one calcium ion.

What is the element symbol for calcium?

• Cu

• Cl

• C

• Ca

Which of the following is a polyatomic ion not found on the periodic table?

• Chloride

• Cyanide

• Carbonate

• Chlorate

What is the ionic charge of calcium?

• 1-

• 2+

• 1+

• 2-

What is the ionic charge of the cyanide ion?

• 1+

• 2-

• 2+

• 1-

Why must the charges in calcium cyanide add up to zero?

• To make it a metal

• To ensure it is a neutral compound

• To make it a polyatomic ion

• To give it a positive charge

How many cyanide ions are needed to balance the charge of one calcium ion?

• One

• Two

• Four

• Three

What is the correct formula for calcium cyanide?

• CaCN

• CaCN2

• Ca2CN2

• Ca2CN

Why are parentheses used in the formula for calcium cyanide?

• To separate metal and non-metal

• To denote multiple cyanide ions

• To show the number of calcium ions

• To indicate the charge