Dissolved oxygen in water, Chemistry

Q. What do you understand by dissolved oxygen in water? How does it create trouble in boiler? Give chemical methods with suitable reactions to remove it from the water.

Ans.

Presence of dissolved oxygen: At room temperature about 8 ppm of dissolved oxygen is present in water. Oxygen enters the boiler through raw make up water. When water containing the free gas is evolved under prevailing high temperature of boiler and attacks the boiler material.

2Fe + 2H2O + O2 = 2Fe (OH) 2

4Fe (OH) 2 + O2 + 2H2O = 2[Fe2O3.2H2O]

Removal of dissolved oxygen:

1. Chemical means: Oxygen can be removed by adding calculated amounts of certain chemicals such as Na2SO3, Na2S and N2H4.

         Na2SO3 + O2 = 2Na2SO4

      Na2S + 2O2 = Na2SO4

However, the sodium sulphate so formed may decompose in high pressure to form H2SO4. Hydrazine (N2H4) is found to be an ideal compound for removing dissolved oxygen since the products are water and nitrogen gas

                                          N2H4 + O2 = N2 + 2H2o

Mechanical means: It works on Henry's law and Dalton's law. Solubility of gas is directly proportional to pressure. Mechanical desecrator is used 

Posted Date: 7/21/2012 7:06:42 AM | Location : United States







Related Discussions:- Dissolved oxygen in water, Assignment Help, Ask Question on Dissolved oxygen in water, Get Answer, Expert's Help, Dissolved oxygen in water Discussions

Write discussion on Dissolved oxygen in water
Your posts are moderated
Related Questions
Structure of chlorine triflouride by VSEPR theory


Q. Illustrate Kinetic Molecular Theory of Gases? Ans. The behavior and properties of gases can be explained by the Kinetic Molecular Theory (KMT). A gas that behaves accord


Write the electron configuration for Tl why do we use F block and how do i count the subshells in that case?

net ionic equation for the reaction between aqueous solutions of perchloric acid and rubidium hydroxide

Q. Determine Infrared moisture balance in flour? Infrared moisture balance is an instrument for measuring the moisture content of materials that do not change their chemical

catalyst used in polymerization

how much glucose C6H12O6 you need to start with to prepare 4.6 times 10 to power 4 Kg of C2H5OH if the yield in the reaction is %64.5 C6H12O6+3O2= 4CO2+C2H5oh+3H2O

what is the unique properties of colloids