Answer to Question #136891 in Chemistry for Chiara Consolacion

Question

what is the molal concentration of the solution by dissolving 2.69g of Phenol in 200 g of water

Answer 1

Solution:

C_m is the molal concentration expressed in moles of solute dissolved per kilogram of solvent (mol/kg). 

C_m = (m_solute / m_solvent) × (1 / MW), where:

m_solute is the mass of solute in grams (g),

m_solvent is mass of solvent in kilograms (kg),

MW is the molecular weight of solute in g/mol. 

Solute = phenol = C₆H₅OH

Solvent = water = H₂O

The molar mass of phenol is 94.11 g/mol.

Thus:

C_m = (2.69 g / 0.2 kg) × (1 / 94.11 g/mol) = 13.45 × 0.01063 = 0.1429 mol/kg = 0.143 m

C_m = 0.143 m

Answer: 0.143 m is the molal concentration of the solution.