Answer:
Near the boiling point of the solvent
Explanation:
The process of recrystallization is hinged on the fact that the amount of solute that can be dissolved by a solvent increases with temperature. The process involves creation of a solution by dissolving a solute in a solvent at or near its boiling point. At the boiling point of the solvent, the solute has a greater solubility in the solvent; not much volume of the hot solvent is required to dissolve the solute.
Before the solution is later cooled, you can now filter out insoluble impurities from the hot solvent. The quantity of the original solute drops appreciably because impurities have been removed. At this lower temperature, the solution becomes saturated and the solute can no longer be held in solution hence it forms pure crystals of solute, which can be recovered.
Recrystallization must be carried out using the proper solvent. The solute must be relatively insoluble in the solvent at room temperature but more soluble in the solvent at elevated temperature.
Answer:
Collisions between gas particles are elastic; there is no net gain or loss of kinetic energy.
Explanation:
When a gas is paced in a container, the molecules of the gas have little or no intermolecular interaction between them. There is a lot of space between the molecules of the gas.
The gas molecules move at very high speed and collide with each other and with the walls of container.
The collision of these particles with each other is perfectly elastic hence the kinetic energy of the colliding gas particles do not change.
Answer: 0.5 g/cm^3
Density equals mass divided by volume so..
60/120 is 0.5 g/cm^3
Answer:
Nucleus
Explanation: it is the center of the atom, and contains protons and nuetrons
7 valance electrons and a atomic number of 9
