November 10, 2017 Name Lecture Assignment#7 (Chapter Nine) Extra Problemt1. The
ID: 561586 • Letter: N
Question
November 10, 2017 Name Lecture Assignment#7 (Chapter Nine) Extra Problemt1. The solubility of MgSO, is 35.1 g/100 g H20 at 20.0°c and 59.2 g/100 g H20 at 70.0°c a) Is a solution that is made by dissolving 100 g MgSO4 in 275 ml of water saturated or unsaturated at 20.0°C? at 70.0°C? How many grams of the 100 g of MgSO4 remains dissolved in 275mL H2O at 20.0°C? at 70.0°C? (assume density of 1.00g/ml) b) c) How many grams of the 100 g of MgSO4 dissolved in 275mL H20 precipitates out of solution (if any) at 20.0°C? at 70.0°C? (assume density of 1.00g/ml)Explanation / Answer
a)
solubility given = 100g/275mL
density of water = 1g/mL
275 mL x 1g/mL = 275g
dissolving 100g in 275 g water = 100g/275g = 36.36g/100g
this is giving 36.36g solid dissolved in 100g water
but max. that can be dissolved is = 35.1g / 100g water ,hence the solution is saturated
solubility at 20 oC cannot be more than 35.1g/100g and hence the solution is saturated at 20 oC, but It is unsaturated at 70 oC as solubility = 59.2g/100g
as max. solubility at 70 oC is given as 59.2g per 100g water but we have only 36.36g /100g water solution and hence more MgSO4 can be dissolved till it reached 59.2g per 100g water
b)
we have 35.1g/100g as solubility
35.1g in 100g solvent
100g will need = 100/35.1 x 100 = 284.9 g water
but we have only 275 mL = 275 mL x 1g/mL = 275 g
and hence the soultion is saturated and dissolved MgSO4 is given by the solubility given
= 275g x 35.1g/100g = 96.525 g
at 70 oC 59.2g/100g as we have already seen that the solution is unsaturated at 70 oC and all 100g will be dissolved
c)
undissolved = 100g in sample - 95.525g in solution = 3.475g undissolved
at 70 oC no undissolved as solution is completely soluble that is 100g solid dissolved and undissolved =0
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.