Colligative Properties and Dissociation of Electrolytes

The molality is the number of moles of solute per kilogram of benzene, so the number of moles of solute in 50.0 g (0.0500 kg) of benzene can be calculated. 

EXAMPLE 14-11 Molecular Weight from a Colligative Property 

We can distinguish between the two possibilities by determining the molecular weight of the unknown solute. We do this by the method shown in Example 14-10, except that now we use the observed boiling point data. 

The molecular weight of the solute is its mass divided by the number of moles. 

The value 130 g/mol for the molecular weight indicates that naphthalene was used to make these mothballs. 

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Colligative Properties and Dissociation of Electrolytes 14-15 Osmotic Pressure... 

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