SOLUTION: A 900-gram salt-and-water solution contains 80 g of salt. This mixture is left in the open air, and 100 g of water evaporates from the solution. What is the percent concentration o

Algebra ->  Equations -> SOLUTION: A 900-gram salt-and-water solution contains 80 g of salt. This mixture is left in the open air, and 100 g of water evaporates from the solution. What is the percent concentration o      Log On


   

Question 1196958: A 900-gram salt-and-water solution contains 80 g of salt. This mixture is left in the open air, and 100 g of water evaporates from the solution. What is the percent concentration of salt in the remaining solution?
_______%?
Answer by ikleyn(52780) About Me  (Show Source):
You can put this solution on YOUR website!
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A 900-gram salt-and-water solution contains 80 g of salt.
This mixture is left in the open air, and 100 g of water evaporates
from the solution. What is the percent concentration of salt in the remaining solution?
~~~~~~~~~~~~~~~~~~ 

    +------------------------------------+
    |   Water evaporates, the salt not.  |
    +------------------------------------+


After evaporation 100 g of water, the mass of the mixture is 900 - 100 = 800 grams.


Of this mass, 80 grams is salt: it remains with no change.


So, the mass concentration of the remaining mixture is  


    80%2F800 = 1%2F10 = 0.1 grams of salt per gram of the resulting mixture.    ANSWER

Solved.

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The major lesson to learn from my solution is THIS :


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                        Water evaporates,  the salt not.

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