The "2" in front of a chemical formula, like in 2AgNO₃ (silver nitrate), indicates that there are two moles of that substance present.

Here's a breakdown:

* AgNO₃: This is the chemical formula for silver nitrate, representing one molecule of silver nitrate.

* 2: This coefficient indicates the number of moles of the substance.

* 2AgNO₃: This represents two moles of silver nitrate, meaning there are two times the number of silver, nitrogen, and oxygen atoms as in one mole of silver nitrate.

In simpler terms: It's like saying you have two "packages" of silver nitrate, with each package containing one mole of silver nitrate.