SOLUTION: A substance in a chemical reaction is used up at a rate that is proportional to the
amount of the substance present at any time. If ½ of the substance is used up in 2
hours, h
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-> SOLUTION: A substance in a chemical reaction is used up at a rate that is proportional to the
amount of the substance present at any time. If ½ of the substance is used up in 2
hours, h
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Question 1187683: A substance in a chemical reaction is used up at a rate that is proportional to the
amount of the substance present at any time. If ½ of the substance is used up in 2
hours, how much of the substance is left at the end of 2 hours and 30 minutes? Answer by ikleyn(52855) (Show Source):
You can put this solution on YOUR website! .
A substance in a chemical reaction is used up at a rate that is proportional to the
amount of the substance present at any time. If ½ of the substance is used up in 2
hours, how much of the substance is left at the end of 2 hours and 30 minutes?
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Since the substance in a chemical reaction is used up at a rate that is proportional
to the amount of the substance present at any time, we have classical exponential decay of the substance.
We also are given that the half-life time of this substance decay is 2 hours.
Since 2 hours and 30 minutes is = 1.25 half-periods, the remaining mass
at the end of 2 hours and 30 minutes will be
= 0.420448 = 0.420 (rounded)
of the original amount of the substance in the reaction.
