How many moles of carbon dioxide are produced when 2.00 grams of baking soda completely reacts?

2 grams of baking soda would contain 0.024 moles

The number of moles of a substance is the ratio of its mass and molar mass.

mole = mass/molar mass

Baking soda has a molar mass of 84.007 g/mol

Thus, 2.00 grams of baking soda will have:

                         2/84.007 = 0.024 moles

More on number of moles can be found here;