00:01
In answering this question, we're going to be looking at a reaction in which we've got nh3 dissolving in solution to produce nh4 positive ions and the oh negative ions.
00:11
Now looking at the information that we've been given would want to first of all determine the initial concentrations before we determine the concentrations at equilibrium.
00:20
Now recall that the molarity, it is equal to the number of moles divided by the volume in litters of the solution.
00:26
Now to determine the number of more, this is going to be equal to the mass.
00:30
Divided by the molar mass and this mass is equal to density multiplied by the volume.
00:36
Now if we determine this mass we are saying mass is going to be equal to 10 milliliters multiplied by 0 .9 gram per milliliter which gives us 9 grams of ammonia and the number of moles are going to be equal to 28 % of the 9 grams divided by the molar mass which is 70 giving us the number of moles of 0 .15.
01:02
Now that we have the 0 .15, we can determine the molarity, which is going to be 0 .15 divided by 1 litre, which then gives us 0 .15.
01:12
So the initial concentration of ammonia is going to be equal to 0 .15...