Answer:
Suppose that you add 29.2 g of an unknown molecular compound to 0.250 kg of benzene, which has a K f of 5.12 oC/m. With the added solute, you find that there is a freezing point depression of 2.78 oC compared to pure benzene. What is the molar mass (in g/mol) of the unknown compound
Explanation:
The mass of nonvolatile solute added is ---- 29.2g
The mass of solvent benzene is ---- 0.250kg = 250g
The Kf value of benzene is ---- 5.12^oC/m.
Depression in the freezing point of the solution is --- 2.78^oC.
What is the molar mass of the unknown solute?
![The depression in freezing point = Kf * molality of the solution\\molality of the solution = \frac{mass of solute}{molar mass of solute}*\frac{1}{mass of solvent in kg}](https://tex.z-dn.net/?f=The%20depression%20in%20freezing%20point%20%3D%20Kf%20%2A%20molality%20of%20the%20solution%5C%5Cmolality%20of%20the%20solution%20%3D%20%5Cfrac%7Bmass%20of%20solute%7D%7Bmolar%20mass%20of%20solute%7D%2A%5Cfrac%7B1%7D%7Bmass%20of%20solvent%20in%20kg%7D)
Substitute the given values in this formula to get the molar mass of unknown solvent:
![molality=\frac{29.2g}{M} * \frac{1}{0.250kg} \\depression in freezing point:\\2.78^oC=5.12^oC/m * \frac{29.2g}{M} * \frac{1}{0.250kg} \\\\=>M=5.12^oC/m * \frac{29.2g}{2.78^oC} * \frac{1}{0.250g} \\\\\\=>M=215.1g/mol](https://tex.z-dn.net/?f=molality%3D%5Cfrac%7B29.2g%7D%7BM%7D%20%2A%20%5Cfrac%7B1%7D%7B0.250kg%7D%20%5C%5Cdepression%20in%20freezing%20point%3A%5C%5C2.78%5EoC%3D5.12%5EoC%2Fm%20%2A%20%5Cfrac%7B29.2g%7D%7BM%7D%20%2A%20%5Cfrac%7B1%7D%7B0.250kg%7D%20%5C%5C%5C%5C%3D%3EM%3D5.12%5EoC%2Fm%20%2A%20%5Cfrac%7B29.2g%7D%7B2.78%5EoC%7D%20%2A%20%5Cfrac%7B1%7D%7B0.250g%7D%20%5C%5C%5C%5C%5C%5C%3D%3EM%3D215.1g%2Fmol)
Hence, the molar mass of unknown solute is --- 215g/mol.
Answer:
changes from a solid to a liquid
Explanation:
Recycling!! And also planting more trees.
Hope this helps!
Answer:
Answer to The solid oxide of generic metal M is added to 69 mL of water and reacts to produce a Neutralization Of The Solution Required Titration With 31 ML Of 0.89 M HCl. How Many Valence Electrons Must M Have? to 69 mL of water and reacts to produce a basic solution that is 0.20 M in the resulting compound.
Explanation:
mark brainliess plss!
Yes the two objects are in thermal equilibrium, True.