Copper bromide, calculating solubility

Copper(I) bromide, CuBr, has a measured solubility of 2.0 x 10 mol/L at 25 °C. That is, when excess CuBr(s) is placed in 1.0 L of water, we can determine that 2.0 x 10 mol of the solid dissolves to produce a saturated solution. Calculate the solid s K p value. 

Problem 11,6 Styrene (St) was polymerized by ATRP using a copper(I) bromide (CuBr) catalyst, com-plexed with A, A, A, A, iV"-pentamethyldiethylenetriamine (PMDETA) ligand, and methyl 2-bromopropion-ate (MBrP) as initiator. Experiments were performed in 1 E mixed vessel at 110°C with excellent temperature control using a monomer to solvent (toluene) ratio of 70 30 wt% and molar ratios of 50 1 1 1 for St/MBrP/CuBr/PMDETA. Under these reaction conditions, only a portion of the catalyst species was soluble and 90% monomer conversion was obtained in 6 h. Calculate a theoretical molecular weight (MW) of the polymer obtained. How would you explain if the experimental MW is found to be higher than the theoretical... 

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