Skip to main content

LATEST POST

MATHS TALENT TEST SCORES RELEASED OVERALLS

Post a Comment

ABOUT CORROSION

CORROSION




It is defined as the chemical or electrochemical attack of metals by the environment.

the effects of corrosion by these factors;


  • humidity
  • temperature
  • purity of  metal
  • the physical state of metal
  • nature of ions present in it
  • PH
  • position in electrochemical series
  • relative areas of anode and cathode

electrochemical theory of corrosion;


this theory depends on its electrode potential of metal(anode).if a high electrode metal comes in contact with the low electrode(cathode) potential metal causes the galvanic cell setup.

note: the large corrosion occurs at anodic metal.

the galvanic cells are three types:


composition cell;

in this, both the zinc and copper electrodes are dipped in the same electrolysis solution. 
here the zinc is act as anode and the copper is act as like cathode.the electrons are transferred from anode to cathode.here the anode gets corroded.

stress cell;

These types of cells formed by the drawing, rolling, welding, heat treatment of metals.
stressed areas at the metal act as like an anode causes corrosion.

concentration cell;

this type of cells formed the differential oxygen concentration.poor oxygenated parts act like anodes and causes the corrosion.

RUSTING OF IRON:


  • (Fe2O3xH2O)
  • corrosion of iron is called rusting.

prevention methods for avoiding:

  • using metal high purity
  • alloying
  • protective coating by the metallic or non-metallic or organic.

READ THIS ARTICALES

INTRODUCTION WITH TYPES AND QUALITY OF EDUCATION

Education is that the process of facilitating learning, or the acquisition of data, skills, values, beliefs, and habits. Educational methods include storytelling, discussion, teaching, training, and directed research. Education frequently takes place under the guidance of educators however, learners can also educate themselves. Education can happen in formal or informal settings and any experience that features a formative effect on the way one thinks, feels, or acts could also be considered educational. The methodology of teaching is called pedagogy. Formal education is usually divided formally into such stages as preschool or kindergarten, grade school, lyceum, then college, university, or apprenticeship. A right to education has been recognized by some governments and therefore the United Nations. In most regions, education is compulsory up to a particular age. Education began in prehistory, as adults trained the young within the knowledge and skills deemed necessary in their socie...
1 comment
Read more

ALKANES AND ALKENES,ALKYNES

ALKANES: these are also called paraffin. alkanes are saturated hydrocarbons. the formula of alkanes (CnH2n+2). when the H atom is removed from the alkane then it is replaced by the name of alkyl. the formula for alkyl is (Cn H2n+1). the carbon atom in it shows the sp3 hybridization. the bond length is equal to 1.54°A. ALKENES: these are also called as olefins means form oil products. it possess a double bond between them. the formula is (CnH2n). the carbon atom in it shows the sp2 hybridization. the bond length is equal to 1.34°A. ALKYNES: these are also called as acetylenes. the formula for this is (Cn H2n-2). the carbon atom in it possesses a triple bond and also shows the linear shape means it is in an sp hybridization. the bond length is equal to 1.20°A.
Post a Comment
Read more