Here's how to calculate the mass of NaCl needed to raise the boiling point of water by 2.00 degrees Celsius:

1. Understand the Concept of Boiling Point Elevation

Boiling point elevation is a colligative property, meaning it depends on the number of solute particles in a solution, not the specific type of solute. The equation for boiling point elevation is:

ΔT_b = i * K_b * m

Where:

* ΔT_b is the boiling point elevation (2.00 °C in this case)

* i is the van't Hoff factor, representing the number of ions a solute dissociates into (NaCl dissociates into 2 ions: Na⁺ and Cl⁻, so i = 2)

* K_b is the molal boiling point elevation constant for water (0.512 °C/m)

* m is the molality of the solution (moles of solute per kilogram of solvent)

2. Solve for Molality (m)

Rearrange the equation to solve for molality:

m = ΔT_b / (i * K_b)

m = 2.00 °C / (2 * 0.512 °C/m)

m = 1.953 m

3. Calculate Moles of NaCl

Since molality is moles of solute per kilogram of solvent, we can calculate the moles of NaCl:

moles of NaCl = molality * mass of solvent (in kg)

moles of NaCl = 1.953 m * 1.000 kg

moles of NaCl = 1.953 moles

4. Convert Moles to Grams

Use the molar mass of NaCl (58.44 g/mol) to convert moles to grams:

mass of NaCl = moles of NaCl * molar mass of NaCl

mass of NaCl = 1.953 moles * 58.44 g/mol

mass of NaCl ≈ 114 g

Therefore, approximately 114 grams of NaCl would need to be dissolved in 1.000 kg of water to raise the boiling point by 2.00 degrees Celsius.