Here's how to calculate the number of moles in 2.10 kg of NaHCO3:

1. Convert kilograms to grams:

* 1 kg = 1000 g

* 2.10 kg * (1000 g / 1 kg) = 2100 g

2. Calculate the molar mass of NaHCO3:

* Na: 22.99 g/mol

* H: 1.01 g/mol

* C: 12.01 g/mol

* O: 16.00 g/mol (x3)

* Total molar mass: 22.99 + 1.01 + 12.01 + (16.00 x 3) = 84.01 g/mol

3. Divide the mass of NaHCO3 by its molar mass:

* Moles = mass / molar mass

* Moles = 2100 g / 84.01 g/mol

* Moles ≈ 25.0 moles

Therefore, there are approximately 25.0 moles in 2.10 kg of NaHCO3.