Tow questions (Physical chemistry), assignment help

Q1: For each of these two elements ( Fe) (Cr) , choose a reaction involving atoms of that element (not necessarily in the form of the free element) – and usually several other elements of course. Report:

 For each element:

(i) The full balanced chemical equation for the reaction, including the likely phase indication for each species – “(g)”, “(l)”, “(s)”, “(aq)” or “(soln)”. Where these are not the expected states at usual temperatures and pressures, add a brief justification – e.g. if you include H₂O (s), something like “reaction occurs at 200 K”.

(ii) The mathematical expression for the equilibrium constant of the reaction as written.

                       

Q2:  The reaction

I₂(g)  +  H₂(g) = 2 HI(g) 

has an equilibrium constant K_c = 50 at 450 K (standard state = 1 mol dm^-3). A reaction vessel of volume 16.0 dm³ contains 8.0 mol iodine, 12.0 mol hydrogen and 1.6 mol hydrogen iodide at 450 K.

 (a)  Calculate the reaction quotient and determine in which direction the reaction will proceed.     

(b)  Calculate the composition ofthe mixture when equilibrium is reached.  

(c)  This reaction is found to be exothermic. Using Le Chatelier’s principle, explain how you would alter the temperature to increase the yield ofHI.