Chemistry

All about chemistry related fields. Organic chemistry mechanism, chemistry masses, chemistry atoms, chemistry answers etc.

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Chemistry Formulas: Acid formulas.

Nitrous Acid -                  HNO₂
Hypochlorous Acid -        HClO
Chlorous Acid -               HClO₂
Chloric Acid -                 HClO₃
Sulfuric Acid -                 H₂SO₄
Sulfurous Acid -              H₂SO₃
Phosphoric Acid -           H₃PO₄
Phosphorous Acid -        H₃PO₃
Carbonic Acid -             H₂CO₃
Acetic Acid -               HC₂H₃O₂
Oxalic Acid -                H₂C₂O₄
Boric Acid -                 H₃BO₃
Silicic Acid -                H₂SiO₃
Nitric Acid -                HNO₃
Perchloric Acid -         HClO₄

Chemistry Answers: Mcq's of Acid, Basis and Salts:

Which of the following reacts with HCl to give Hydrogen?
A-ammonia
B-iron
C-potassium manganate(VII)
D-silver
E-sodium hydroxide

SOLUTION:
The correct answer is iron (B)

REASON:
Metals which are more active than hydrogen can displace it from acids.

Chemistry atoms: Basic Ideas.

1-All matter is made up of very small, discrete particles called atoms.
2-All atoms of an electron are alike in weight and different from the weight of any other kind of atom.
3-Atoms unite in chemical changes to form compounds.The atom loss its characteristic properties when this combination occurs.
4-The atom is not entirely altered in the formation of a compound, and its weight remains constant.

Chemistry Mass: Molar Mass and Moles:

When the formula weight of an ionic compound is determined by the addition of its component relative atomic masses and expressed in grams, it is called the gram formula weight or Molar Mass. For example CaCO3.


1Ca = 40
1C = 12
3O = 48 = (3*16)
_______________________

 CaCO3 = 100 formula weight
100g = Molar Mass

Organic Chemistry Mechanism: Elbs reaction:

In this method poly nuclear hydrocarbons are produced from a diaryl ketone containing a methyl group in the ortho position to the keto group. The reaction is usually carried out by heating the ketone under reflux at 400-450 0C until water is no longer evolved, e.g: o-methyl benzophenone forms anthracene.

MCQ'S: Acids, Bases and Salts:

The compound SO2Cl2 reacts with water according to the following reaction.


SO2Cl2 + 2H2O  ---------->  H2SO4 + 2HCl

How many moles of  NaOH will neutralise the solution produced by one mole of  SO2Cl2 and excess of water.
A-1
B-2
C-3
D-4
E-5
SOLUTION:

The correct answer is (D)


REASON:

Two moles of NaOH will neutralize one mole of H2SO4 and two moles of NaOH are required for two moles of HCl.

MCQ'S: Acids, Bases and Salts.

One mole of each of the following compound was dissolved in water to make 1dm3 of solution.which of the solution would have lowest PH?

A-ammonia
B-ethanoic acid
C-sodium hydroxide
D-sulphuric acid

SOLUTION:

The answer is E (suphuric acid)

REASON:

The solution with lowest PH must be of a strong acid(H2SO4)


Rooms

MCQS: Which statement about graphite is correct?

A- It conducts electricity because graphite has ions which are free to move.
B- It has an ionic lattice.
C- It has the same structure as diamond.
D- Its structure contains rings of carbon atoms.


SOLUTION:
D- is correct statement due to the reason, In graphite, each layer contains hexagonal ring of carbon atoms with each atom covalently bonded to 3 other atoms.

How to make standard solutions for Chemistry:

There are  two common types of "standard solutions".
1- Molar Solutions
 2-Normal Solutions
 Both of these solutions are concentrations (or “strengths”) of a particular component
(solute) that is dissolved in a solvent.
Making a Molar solution usually involves fewer mental steps than does making a Normal
solutions.