Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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
In hydrogen spectrum the different lines of Lyman series are present is : (1 )UV field (2) IR field (3) Visible field (4) Far IR field Ans: UV field
Question 1: (i) What are the main physical properties of hydrogen sulphide? (ii) Which occupational group of workers is often exposed to hydrogen sulphide? (iii) O
occurrence of p block elements
WHAT ARE THE ELEMENTS OF DETERMINED QUALITATIVE ANALYSIS
what is sp- sp bonding
Q. Objectives of coordination compounds? Define the terms coordination compounds, coordination number. ligand and oxidation state, Describe IUPAC rules for naming coor
Crystals and glasses Unlike a complex ion or molecule, which is a finite (often small) assembly of atoms, a solid has no fixed shape and size but can add atoms indefinit
Stability of a nucleus and its binding energy
Precipitation titrations - Types of titrations The titrations that are based upon the formation of insoluble precipitates, while the solvent of two reacting solution are brough
role of modifiers in solvent extraction of metal ion
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd