Question

Calculate the melting point of a mixture of 1 mol of benzene and 2 mol of toluene, given that the pure components have melting points of 5.5 °C and -95.0 °C, respectively.

Answer 1

To calculate the melting point of a mixture of benzene and toluene, we can use the weighted average method. This method takes into account the mole fraction of each component and their respective melting points.First, let's calculate the mole fraction of each component:Mole fraction of benzene  X_benzene  = moles of benzene / total molesX_benzene = 1 mol /  1 mol + 2 mol  = 1/3Mole fraction of toluene  X_toluene  = moles of toluene / total molesX_toluene = 2 mol /  1 mol + 2 mol  = 2/3Now, we can calculate the weighted average melting point of the mixture:Melting point of mixture =  X_benzene * melting point of benzene  +  X_toluene * melting point of toluene Melting point of mixture =  1/3 * 5.5 C  +  2/3 * -95.0 C Melting point of mixture =  1/3 * 5.5  +  2/3 * -95 Melting point of mixture = 1.83 - 63.33Melting point of mixture = -61.5 CTherefore, the melting point of the mixture of 1 mol of benzene and 2 mol of toluene is approximately -61.5 C.