Chemistry Questions Answers

• 1. Who is regarded as father of modern chemistry ?

  1. Ruterford
  2. Einstein
  3. Lavoisier
  4. C.V. Raman

  
  

  Answer: Option C

  
  

• 2. Which is not a type of elements ?

  1. Metals
  2. Non Metals
  3. Metalloids
  4. Gases

   

  Answer: Option D

  
  

• 3. Which acid is present in lemon ?

  1. marlic acid
  2. citric acid
  3. lactic acid
  4. tartaric acid

   Answer And Explanation

  Answer: Option B

  Explanation:

  citric acid is present in lemon.

  
  

• 4. Identify the wrong statement in the following

  1. Atomic radius of the elements increases as one moves down the first group of the periodic table
  2. Atomic radius of the elements decreases as one moves across from left to right in the 2nd period of the
  3. Amongst isoelectronic species, smaller the positive charge on the cation, smaller is the ionic radius
  4. Amongst isoelectronic species, greater the negative charge on the anion, larger is the ionic radius

   

  Answer: Option C

  Explanation:

  
  

• 5. Rare gases are

  1. mono atomic
  2. di atomic
  3. tri atomic
  4. None of above

  
  

  Answer: Option B

  Explanation:

  Rare gases are di atomic.

  
  

• 6. The term PVC used in the plastic industry stands for

  1. polyvinyl chloride
  2. polyvinyl carbobate
  3. phosphor vanadiu chloride
  4. phosphavinyl chloride

   Answer And Explanation

  Answer: Option A

  
  

• 7. What among following is used to produce artificial rain ?

  1. copper oxide
  2. carbon monoxide
  3. silver iodide
  4. silver nitrate

   Answer And Explanation

  Answer: Option C

  • 8. Oil of vitriol is 

  
  

  • 1. nitric acid
    2. sulphuric acid
    3. hydrochloric acid
    4. phosphoric acid

     Answer And Explanation

    Answer: Option B

    
    

  • 9. Which is used in preparation of dynamite ?

    1. glycerol
    2. ethyl alcohol
    3. methyl alcohol
    4. glycol

    
    

    Answer: Option A

    
    

  • 10. What is Calcium sulphate ?

    1. epsom salt
    2. blue vitriol
    3. gypsum salt
    4. potash alum

     Answer

    Answer: Option C

    Explanation:

    
    

  • 11. Bleaching action of chlorine is by

    1. decomposition
    2. hydrolysis
    3. reduction
    4. oxidation

     Answer And Explanation

    Answer: Option A

    
    

  • 12. Which metal is heaviest ?

    1. osmium
    2. mercury
    3. iron
    4. nickle

     Answer: Option B

CUBANE

• Cubane (C8H8) is a synthetic hydrocarbon molecule that consists of eight carbon atoms arranged at the corners of a cube, with one hydrogen atom attached to each carbon atom.

• A solid crystalline substance, cubane is one of the Platonic hydrocarbons.

• It was first synthesized in 1964 by Philip Eaton

• Once formed, cubane is quite kinetically stable, due to a lack of readily available decomposition paths.

Properties of cubane and its derivatives

1. The 90-degree bonding angle of the carbon atoms in cubane means that the bonds are highly strained. Highly reactive so useful in high density high energy fuels and explosives.

7 Crystal Systems Of Solids

7 Crystal Systems Of Solids
Remember this 'C TOM THR' (pronounce as 'see tom teacher)

C for Cubic
T for Tetragonal
O for Orthorhombic
M for Monoclinic
T for Triclinic
H for Hexagonal
R for Rhombohedral

A familiar example for each

Cubic: NaCl
Tetrogonal: TiO2
Orthorhombic: BaSO4
Monoclinic: NaHCO3
Triclinic: K2Cr2O7
Hexagonal: Graphite
Rhombohedral: KMnO4.

MOST ORDERED STRUCTURE: CUBIC

MOST DISORDERED : TRICLINIC

Structure resembling Matchbox: Orthorhombic

Complexometric titration

Complexometric titration 
Complexometric titration (sometimes chelatometry) is a form of volumetric analysis in which the formation of a colored complex is used to indicate the end point of a titration. Complexometric titrations are particularly useful for the determination of a mixture of different metal ions in solution. An indicator capable of producing an unambiguous color change is usually used to detect the end-point of the titration.

Reactions for Complexometric Titration::

In theory, any complexation reaction can be used as a volumetric technique provided that:

1- the reaction reaches equilibrium rapidly after each portion of titrant is added.
2- interfering situations do not arise. For instance, the stepwise formation of several different complexes of the metal ion with the titrant, resulting in the presence of more than one complex in solution during the titration process.
3-a complexometric indicator capable of locating equivalence point with fair accuracy is available.

-----------------------------
If you have more information, you can add it, please press the "share" if you like the information