Question

If I make a solution by adding 83 grams of sodium hydroxide to 750 mL of water. a. What is the molality of sodium hydroxide in this solution

Answer 1

2.77 mol/kg

Step-by-step explanation:

Molality is a sort of concentration that indicates the moles of solute in 1kg of solvent. In this case our solvent is water and, if we consider water's density as 1g/mL, we determine that the mass of solvent is 750 g.

We convert the mass to kg → 750 g . 1kg /1000g = 0.750 kg

Our solute is the NaOH → 83 g.

We convert the mass to moles → 83 g . 1mol /40g = 2.075 mol

Molality (mol/kg) = 2.075 mol / 0.75kg = 2.77 m