Question

The solubilities of three salts in water are shown in the graph. 

For each salt, determine how much will remain undissolved if 500 g is mixed into a liter of pure water at 40°C. One significant figure is sufficient in each answer. 

Answer 1

The structural formula of propylene gly is as follows: HO VOH propane-1,3-diol For K2Cr201 Looking at the red line in the graph, at x=40 C, we have the solubility value about 200 g/L. Solubility: When the maximum amount of solute is dissolve in the solvent is called solubility. On the basic of solubility the solution are following types: Hence, if we add 500 g of K2Cr207, the amount of salt undissolved will be 500-200 = 300 g Hence, Pb(NO3)2 : 0 g Saturate solution: A solution which contains the maximum amount of dissolved solute at the equilibrium is called saturated solution. KCI: 100 g Un-saturate solution: A solution which contains lesser amount of solute as compare to saturated solution. It will be able to dissolver more solute. K2Cr207 : 300 g Super-Saturate solution: A solution which contains the more dissolved amount of solute as compare to saturated solution. For Pb(NO3)2 At temperature 40 C, looking at the blue line in the graph, we get a value of solubility that is in between 700-800 g/L Hence, we can take it to be approximately 750 g/L. Hence, if 500 g of Pb(NO3)2 is added to 1 L of water at 40 C, all of it will dissolve as the solubility is more than 500 g/L. Hence, amount of un-dissolved Pb(NO3)2 will be o g. For KC1 Looking at the green line in the graph, at x = 40 C, we have the solubility at about 400 g/L. Hence, if we add 500 g of KCl to 1 L of water, the amount of salt undissolved will be 500-400 = 100 g. For K2Cr207

Answer 2