In your boiling point elevation measurement, describe all the temperature measur
ID: 496496 • Letter: I
Question
In your boiling point elevation measurement, describe all the temperature measurements you need to make to determine delta T_b (the change in boiling point), including what observation will indicate the boiling point has been reached. You are convinced that your calcium chloride solution will keep the water liquid at extreme temperatures. However, your boss is also concerned about the interaction of the solution with the metal of the engine. Look up the Stability and Reactivity section of the calcium chloride SDS. Does your boss need to worry about calcium chloride harming the engine? Write down the exact phrasing that supports your response. After some more research, you realize most ionic solutions might harm the metal in the engine and look into water-soluble molecules. Will the water-soluble molecules be as effective per mole at elevating the boiling point as the calcium chloride solution? Explain.Explanation / Answer
3)Boiling-point elevation describes the phenomenon that the boiling point of a liquid (a solvent) will be higher when another compound is added, meaning that a solution has a higher boiling point than a pure solvent. This happens whenever a non-volatile solute, such as a salt, is added to a pure solvent, such as water. The boiling point can be measured accurately using an ebullioscope.
The extent of boiling-point elevation can be calculated by applying Clausius–Clapeyron relation and Raoult's law together with the assumption of the non-volatility of the solute. The result is that in dilute ideal solutions, the extent of boiling-point elevation is directly proportional to the molal Concentration of the solution according to the equation:[1]
Tb = Kb · bB
where
Equation after including the van 't Hoff factor
Tb = Kb · bsolute · i
At high concentrations, the above formula is less precise due to nonideality of the solution. If the solute is also volatile, one of the key assumptions used in deriving the formula is not true, since it derived for solutions of non-volatile solutes in a volatile solvent. In the case of volatile solutes it is more relevant to talk of a mixture of volatile compounds and the effect of the solute on the boiling point must be determined from the phase diagram of the mixture. In such cases, the mixture can sometimes have a boiling point that is lower than either of the pure components; a mixture with a minimum boiling point is a type of azeotrope.
The temperature at which a liquid boils, with the vapor pressure equal to the given external pressure.
The temperature at which a substance's vapor pressure equals the external pressure increases when another compound is added.