00:01
Hi, so we are calculating the malarity of the solutions here.
00:06
Okay, so we have four solutions.
00:09
Okay, so what you have to remember is that the formula for molarity, m is equivalent to number of moles of the solute over the volume of the solution, which should be in liters.
00:22
Okay, so using this formula, calculating the molarity of the first solution, we have 8 .10 grams of the solution.
00:31
Which is ammonium magnesium phosphate so the molar mass of this compound is 137 .3 so just divided here then we have moles in the numerator over the volume which is 600 ml and take note they should be in liters so we'll convert that to liters ml to liters this is the conversion factor now we cancel some units grams grams ml the remaining unit as you can see is moles per liter.
01:00
That's a unit for molarity.
01:02
Okay, so calculating this will get 0 .0983 moles per liter.
01:13
Second solution, we have sodium acetate, that's 19 .4 grams, divide the molar mass of sodium acetate, 82 grams, then we have here moles over the volume of the solution, 250 ml, convert to liters, 1000 ml is 1 liter.
01:37
Okay, now we cancel some units, grams here, ml here, and then the remaining unit, again, is moles per liter.
01:44
So we have 0 .946.
01:47
This is moles per liter or molar.
01:54
Third one, it's just the same process...