The solubility of Magnesium Carbonate in water is 0.39 grams per liter. The question is, what is the Ksp of MgCO3?
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00:00The solubility of magnesium carbonate in water is 0.39 grams per liter.
00:07The question is, what is the Ksp of MgCO3?
00:13Okay, the first step is identification.
00:19The solubility of magnesium carbonate is 0.39 grams per liter.
00:25The relative molecular mass of magnesium carbonate is 24.3, plus 12, plus 3 times 16.
00:36That is 84.3 grams per mole.
00:40The next step is to calculate the molar solubility.
00:45Solubility is equal to Mr times the molar solubility.
00:48Plug in the solubility and relative molecular mass.
00:52The molar solubility is equal to 4.626 times 10 to the power of negative 3 moles per liter.
01:00The third step is to analyze the ionic equilibrium.
01:05In water, a molecule of magnesium carbonate ionizes into a Mg2 plus ion and a carbonate
01:11ion.
01:13The solubility value is measured when the solution is exactly saturated or supersaturated.
01:19In this condition, the magnesium carbonate molecules and their ions form a chemical equilibrium.
01:28And in 1 liter of water.
01:31So in this solution, there are 4.626 times 10 to the power of negative 344 moles of Mg2
01:38plus ions.
01:41And 4.626 times 10 to the power of negative 3 moles of carbonate ions.
01:49So the molarity of magnesium ions is 4.626 times 10 to the power of negative 3 molar.
01:58While the molarity of carbonate ions is 4.626 times 10 to the power of negative 3 molar.
02:06The fourth stage is to write the chemical equilibrium equation.
02:11This chemical equilibrium equation is very difficult to read.
02:15Let's just look at the monitor screen.
02:19Now we can calculate Ksp.
02:22Ksp is equal to the concentration of magnesium ions, multiplied by the concentration of carbonate
02:28ions.
02:30Enter the ion concentration value.
02:33The result of the calculation is 2.14 times 10 to the power of negative 5.
02:39This is the Ksp of magnesium carbonate.
02:44Yup, hopefully useful.
02:46And don't forget to follow this channel.