The compound cholesteryl benzoate is a rod-like molecule that undergoes a phase change from the solid to the liq- uid crystal phase at 145.5 °C. When cholesteryl benzoate is mixed with cholesteryl oleyl carbonate, a molecule with a curved shape, the temperature of the solid to liquid crys- tal transition changes. Predict if the transition temperature increases or decreases and explain your reasoning.

Video transcript

Hey everyone, we're told that the transition from solid to liquid crystal of compound X, which has a rod like shape occurs at 125°C. The transition temperature changes when compound X. Is combined with compound Y, which has a curve shape predict whether the transition temperature will increase or decrease and explain why. Now before we look at our answer choices, let's go ahead and recall some information about the transition temperature from solid to liquid crystal. Now, if we're more disordered, our transition temperature from solid to liquid crystal will decrease. Now if we're more ordered, our transition temperature from solid to liquid crystal will increase. Now let's go back to our question stem and think about what's occurring. We're combining a curve shaped compound to a rod like shape compound. So that means our disorder will increase. And since we're becoming more disordered, our transition temperature will decrease. So looking at our answer choices, it looks like answer choice A perfectly describes this. The transition temperature from solid to liquid crystal will decrease because the mixture is more disordered. Now, I hope that made sense. And let us know if you have any questions