Questions asked by Lala L.

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• Sodium peroxide is used in orbital stations for air purification.The reaction that takes place is?
  
• A mix of oxide and peroxide of the same monovalent metal has the mass of 5.6g.The mix is treated with an excess amount of water , forming 6.4g of base. (?)
  
• What do effervescent tablets contain , that make them release CO2 on contact with water?
  
• Although hydrogen has the smallest molar mass, helium has the lowest boiling point.Why?
  
• What is the role of EDTA and H3PO4 in the stabilization of commercialy used (3% solution) hydrogen peroxide?
  
• What is "the thing" in the structure of a compound that decides if it is going to be soluble in water or not?
  
• Describe the biochemical mechanism throgh which HCl is formed in the stomach(in humans) (?)
  
• A ball of mass m is droped from a height h , losing x% of its energy(that it had before the respective drop) on each fall.Calculate how many times the ball will fall until it stops and how long it will take the ball to do that.(?)
  
• Write the reaction mechanism for the following process: #Na_2S_2O_3+2HCl=2NaCl+S+SO_2+H_2O# Justify , based on the mechanism of the reaction , the role of HCl as a catalyst(?).
  
• Order in the increasing order of acidity:HCl, H2SO4, HF, HCl, HI, HBr, HNO3, HBrO, HClO, HClO3, HClO4, H2S, H3PO4(?)
  
• Synthesis of isonicotinic acid from benzene?
  
• X€[-1;0] and -2y€[-2;2] then #(x-2y)^2#€...?
  
• Being given the structure of hemoglobin, determine the hybridization state of the iron atom?
  
• How can you chemically coat copper coins with a layer of zinc?
  
• Why does CS2 reacts with water , but CCl4 doesn't?
  
• A solution of Ca 2+ is added to a solution of SO4 2- and CO3 2- , what will precipitate first , CaCO3 or CaSO4?
  
• Boric acid is written as H3BO3 or B(OH)3...but if it is written as B(OH)3...why is it still an acid and not a base?
  
• Adding a solution of KSCN to a solution of #Fe^{3+}# salt , forms a blood-red complex. What is that complex #K_3[Fe(SCN)_6] \ or \ Fe[Fe(SCN)_6]# ?
  
• Can someone please explain me? I have some questions about the Periodic Table...(sorry for any grammar mistake)
  
• What are polarizing filters made of and how they work at a molecular level?
  
• Hi!Can someone help me?
  
• 1-octanol is also called n-octanol.What does "n" stand for?
  
• Ionization energy ?
  
• Titration problem?
  
• Electron configuration?