Chemistry Questions

Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment.

Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. This removes material that will either float or readily settle out by gravity. It includes the physical processes of screening, comminution, grit removal, and sedimentation.

Secondary treatment removes the soluble organic matter that escapes primary treatment. It also removes more of the suspended solids. Removal is usually accomplished by biological processes in which microbes consume the organic impurities as food, converting them into carbon dioxide, water, and energy for their own growth and reproduction.

Tertiary treatment includes removal of nutrients such as phosphorus and nitrogen and practically all suspended and organic matter from waste water.

An atom that loses or gains electrons is called as ion. Gaining of electron is negative charge and is called as Anion and lossing of eectron is called Cation.

The acid and the nitrite form nitrous acid which then reacts with the amine.

Br-Br.

In Br2, two of the same atoms, pull on each side of the bond is equal making it as non-polar.

The other options all include a significantly more electronegative atom (the oxygens and the chlorine), so those bonds are all polar covalent.

The substances in which two or more atoms are attached together are called as molecular substances. 

Properties of molecular substances ::

1. Molecular substances are bonded with covalent bonds

2. Bad heat conductivity

3. Bad electrical conductivity

4. Have low melting points.