can someone help me answer this solubility question?
The solubility of ammonium bromide in water at 20 °C is
75.5g/100g of water. At 50 °C it is 99.2g/100g.
a. Calculate the mass of ammonium bromide that will
dissolve in 65.0g of water at 20 °C.
b. Calculate the mass of water required to dissolve
50.0 g of ammonium bromide at 50 °C
c. Calculate the mass of ammonium bromide that
would not remain in solution if a solution made up of
29.0g ammonium bromide in 35.0 g water at 50 °C is
cooled to 20 °C.
also..is there a site that covers sample chemistry problems with provided answers?
2006-09-01 07:17:00 · 4 answers · asked by Julio 4 in Science & Mathematics ➔ Chemistry
i don't need the answer..just the process of going about answering them
2006-09-01 07:31:39 · update #1
Problem A
This problem can be solved using proportions
If 75.5g are in 100g, then Xg are in 65.0g at 20'C
75.5g/100g = Xg/65.0g solve for Xg
Xg=49.07g ans. = 49.1g of NH4Br
Problem B is very simular to prob a.
Problem C, you need to calculate the grams of solute at 20"C and compare it to the number og grams at 50'C.
2006-09-01 07:36:47 · answer #1 · answered by Roy G. Biv 3 · 1⤊ 0⤋
Ammonium Bromide Solubility
2017-01-11 13:57:15 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Just let the units do the work for you! You know that 75.5g NH4Br will dissolve in 100g of water at 20 C, and you know how much water you have, so just multiply the solubility by the mass of water to get the mass of NH4Br that will dissolve. For b, multiply the mass of NH4Br by the inverse of the solubility to get grams of water.
For c, find the mass of NH4Br that could be dissolved in 35g of water at 20C and subtract that from the amount that is actually in the solution (29g) to find the amount that precipitates out.
Just pay attention to your units and multiply or divide to cancel stuff out until you get what you need!
As far as a good website, your textbook publisher probably has a website that goes over example problems. Your book may have even come with a CD that works out some problems.
2006-09-01 07:38:49 · answer #3 · answered by Duluth06ChE 3 · 0⤊ 0⤋
a) 100g of Water dissolves 75.5 g
So, 65g dissolves 65*75.5/100 g = 49.075 g
b) 99.2 g in 100g
50 g in 50*100/99.2 g = 50.4 g
c) At 20 deg C 35 g of water will hold 35*75.5/100 g = 26.43 g
Thus mass which shall not remain = 29 - 26.43 g = 2.57 g
2006-09-01 07:43:02 · answer #4 · answered by ag_iitkgp 7 · 0⤊ 0⤋