General Chemistry Interview Preparation Guide
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General Chemistry frequently Asked Questions by expert members with experience in General Chemistry. So get preparation for the General Chemistry job interview

28 General Chemistry Questions and Answers:

1 :: What is the process for separating the components of gunpowder?

First introduce water and then filter the
particulates out. The liquid would be mostly potassium
nitrate since there will be a finite amount of solubility
of the other 2 compounds. Next introduce carbon disulfide
and filter the carbon away from the soluble sulfur. They
would be cleaned up sufficiently enough i would think.

2 :: However ozone is heavier than oxygen still ozone is up there in sky why?

It's not that it's "staying up there", it's that it never
has a chance to fall. Ozone is FORMED up there, and it
breaks apart again before it has a chance to fall.

Ozone is formed when UV radiation hits oxygen (O2),
splitting it apart. Oxygen atoms hate to be alone, so they
recombine with an O2 molecule to make O3, ozone. Before the
ozone has a chance to fall, IT gets hit with MORE uv
radiation, turning it back into oxygen. Ozone just keeps
getting made and destroyed before it has a chance to fall.

3 :: When a glass rod is heated gradually and suddenly dipped in cold water, it cracks. What is the reason?? When a cool glass rod is suddenly heated, it cracks. Why?

When a glass rod is heated the molecules gains etnergy and
they will be in random motion. when it is suddenly dipped
in cold water, the glass molecules contact with water
gives its energy to the lower enrgy water molecule while
the molecules inside the glass with higher energy will
relese the energy randomly as a result it creates cracks
for more surface area, so that more energy can flow in
lower time.

Same thing happens when it cooled rod is heated.

4 :: pH is having unit?


5 :: Which is the best conductor of electricity?

silver is best conductor of electricity.

7 :: What is acidity of a base?

Number of OH- ions released by a base is the acidity of a base

9 :: What is kentchin? Is it real? As much info on it as possible?

hardest metal.
1 square metre of kentchin could with stand the heat of the

12 :: What is the difference between base & nucleophile?

A lewis base is a proton acceptor. these can be good
nucleophiles for a reaction if they are not too big and
bulky. if they are too big, they can't attack the
electrophile and you will probably get an E type rxn
instead of an SN type rxn. A nucleophile is any electron
rich molecule. This can be a lewis base or it can be
another species such as a carbanion

13 :: What is the formula of diesel, petrol & CNG too?

The alkanes from pentane (C5H12) to octane (C8H18) are
refined into petrol, the ones from nonane (C9H20) to
hexadecane (C16H34) into diesel fuel and kerosene (primary
component of many types of jet fuel), and the ones from
hexadecane upwards into fuel oil and lubricating oil.

15 :: In Einsteins mass energy relation e=mc2 for what is c used or why is light required for reactions. Because the reactions are with help of neutrons?

In This equation c is sed as a speed of light
In a chemical reactions most of the reaction are photolytic
reaction,which means bond breaks or formed with influence
of light.hence c is used in reaction

16 :: What is the valence of nitrogen?

Nitrogen has 5 valence electrons in an atom

18 :: why in atomic mass electron is not include while proton and neutron include? although electron is a part of atom?

Electrons are moving around the orbit of the atom.According
to Heisenberg principle position and momentum(P) of a
moving particle cannot be determined simultaneously at one
instance. since mass is to be determined from the formula m
= P/v, where P is the momentum and v is the velocity of the
electron.even if we can able determine the velocity we
can't determine the momentum at that time. hence the mass
can't be determined.hence it is negleced from the atomic
mass calculation.

19 :: Why all the concentration of chemical species are measured using water as solvent (for examole 1N NaOH means 40 g of NaOH in one litre of water)eventhough there are so many solvents available?

Water is a neutral solvent, doesn't react with NaOH or other
chemical species.
its density nearly about 1.0.

Some reagents may be prepare in so many solvents.

for example. 0.1N perchloric acid is prepared in glacial
actic acid in non aqueous titration.

Methanolic HCl(HCl in Methanol)or Hcl in Propanol etc