Answer:
Decantation
Explanation:
Decantation is one of the process of separating mixture containing solid and liquid. In this process, gravity plays a very important role. The solid part of the mixture is allowed to settle down. The liquid is removed and separated in another container. It is a process that helps in the purification of the liquid. The particles that are insoluble settles down and is further subject to be separated from the mixture.
Answer:
Density, melting point. and magnetic properties
Explanation:
I can think of three ways.
1. Density
The density of Cu₂S is 5.6 g/cm³; that of CuS is 4.76 g/cm³.
It should be possible to distinguish these even with high school equipment.
2. Melting point
Cu₂S melts at 1130 °C (yellowish-red); CuS decomposes at 500 °C (faint red).
A Bunsen burner can easily reach these temperatures.
3. Magnetic properties
You can use a Gouy balance to measure the magnetic susceptibilities.
In Cu₂S the Cu⁺ ion has a d¹⁰ electron configuration, so all the electrons are paired and the solid is diamagnetic.
In CuS the Cu²⁺ ion has a d⁹ electron configuration, so all there is an unpaired electron and the solid is paramagnetic.
A sample of Cu₂S will be repelled by the magnetic field and show a decrease in weight.
A sample of CuS will be attracted by the magnetic field and show an increase in weight.
In the picture below, you can see the sample partially suspended between the poles of an electromagnet.
A molecule with two strong bond dipoles can have no molecular dipole if the bond dipoles cancel each other out by pointing in exactly opposite directions. For example, in carbon dioxide (a linear molecule), the carbon-oxygen bonds have a <span>large dipole moment. However, because one dipole points to the left and the other to the right the dipole is cancelled.</span>
The smallest halogen atom is fluorine
Four people weigh a standard mass of 10.00 g on the same balance. The set of readings suggest measurements that are neither precise <span>nor accurate is the one with less mass</span>