On mélange des volumes égaux de deux solutions, toutes deux 0,10 M, de nitrate d'argent AgNO3 et

On mélange des volumes égaux de deux solutions, toutes deux...

Key Concepts

Precipitation Reaction

A precipitation reaction occurs when two aqueous solutions containing ions combine and form an insoluble solid, known as the precipitate. This process involves the formation of an insoluble compound from two soluble salts, driven by the low solubility of the resulting product in water.

Reaction Stoichiometry and Limiting Reactants

Understanding reaction stoichiometry is essential in predicting the outcome of mixing solutions containing reactive ions. When equal volumes of solutions with equal concentrations of the reactants are mixed, the ions react according to their stoichiometric ratios, and one reactant may completely react as the limiting reagent. This determines the quantity of precipitate formed and the composition of the remaining solution.

Solubility Product (Ksp)

The solubility product is a constant that indicates the maximum product of the ion concentrations for a sparingly soluble salt that can exist in equilibrium with its solid phase. When the product of the ion concentrations exceeds the Ksp, precipitation occurs. This concept is critical for assessing whether changes in ion concentration, such as through dilution or the addition of more ions, will lead to the reformation of a precipitate.

Effect of Dilution and Additional Reagent

Dilution affects the concentration of ions in a solution, thereby altering the ionic product relative to the solubility product. Adding an extra amount of one reagent, after an initial reaction and separation, changes the equilibrium conditions. Evaluating if the new ionic concentrations exceed the Ksp determines whether further precipitation will occur after dilution or additional reagent is introduced.

Transcript

00:01 In answering this question, to determine whether or not silver chloride is going to precipitate, what we are going to do is to compare the qsp right after mixing and the ksp, which is the equilibrium constant at equilibrium.

00:15 So if this qsp is greater than the ksp, it means the silver chloride is going to precipitate.

00:23 Now looking at the information that we've been given, right after mixing, the concentration of the chloride ions right after mixing, this is going to be 2m multiplied by 100 mils divided by the new volume of 200 milliliters, which is equal to 1m.

00:39 Remember c1, v1 is equal to c2, v2, where the c is c, where the c3 represents the concentration, and v2 is the final volume, and v2 is the initial volume, if we are talking about the same species.

00:55 And then as for the silver, we are seeing the concentration of silver ions in soviet.

00:59 Right after mixing this is going to be the concentration of the silver nitrate which is 0 .02 multiplied by a hundred milliliters divided by 200 milliliters which gives us 0 .01m now looking at this if we are to look at the reaction we've got silver chloride at equilibrium with ag plus ions and chloride ions now the ksp for this reaction is equal to 1 .8 by 10 to the power negative 10.

01:32 Now the qsp, this is the product of these two, right after mixing, this is going to be 1 multiplied by 0 .01, and this gives us a qsp that is equal to 0 .01 m squared.

01:49 Now if we are comparing these two values, the qsp and the ksp, we can tell that the qsp is greater than the ksp.

01:58 So we can conclude to that sulfur chloride is going to precipitate out of solution.

02:08 So setting this aside, let's look at the equilibrium at different concentrations.

02:14 This is going to be ag plus and cl minus.

02:19 Now looking at the concentrations, we have the initial.

02:23 The initial, this is going to be 0 and we've got 1m.

02:27 If we look at the change, if this changes by x, this will also change by x since they and the ratio of 1 is to 1.

02:35 So what this means is equilibrium.

02:37 We've got x as the concentration of the silver ions.

02:40 And we've got 1 plus x as the concentration of the chloride ions...

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