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. pb(no₃)₂: 250 g kcl: 100 g k₂cr₂o₇: 0 g

Explanation:

Step1: Read solubility from graph

From the graph, at 40°C, the solubility of \(Pb(NO_3)_2\) is about 750 g/L, of \(KCl\) is about 400 g/L and of \(K_2Cr_2O_7\) is about 500 g/L.

Step2: Calculate undissolved amount for \(Pb(NO_3)_2\)

Since solubility of \(Pb(NO_3)_2\) is 750 g/L and we have 500 g, all 500 g will dissolve, so undissolved amount is 0 g.

Step3: Calculate undissolved amount for \(KCl\)

We have 500 g of \(KCl\) and solubility is 400 g/L. Undissolved amount = \(500 - 400=100\) g.

Step4: Calculate undissolved amount for \(K_2Cr_2O_7\)

We have 500 g of \(K_2Cr_2O_7\) and solubility is 500 g/L. So undissolved amount is \(500 - 500 = 0\) g.

Answer:

\(Pb(NO_3)_2\): 0 g
\(KCl\): 100 g
\(K_2Cr_2O_7\): 0 g