document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=886121>Question 886121</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I a longer word problem that I have not been able to get the second part answered correctly.  \r<BR>\n" );
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document.write( "Reacting with water in an acidic solution at a particular temperature, compound A decomposes into compounds B and C according to the law of uninhibited decay.  An initial amount of 0.60 M of compound A decomposes to 0.55 M in 30 minutes.  How much of compound A will remain after 2 hours? .42 is the answer I came up for on this part.\r<BR>\n" );
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document.write( "How long will it take until 0.10 M of compound A remains?\r<BR>\n" );
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document.write( "I got to  .10=0.60e^ln (.55/.60)/30 times t<BR>\n" );
document.write( "I then divided both sides by .60 and <BR>\n" );
document.write( "ln.10/.60=e^ln(.55/.60)/30  times t\r<BR>\n" );
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document.write( "If I'm on the right track I'm kind of stuck now.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #535689 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=535689\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Reacting with water in an acidic solution at a particular temperature, compound A decomposes into compounds B and C according to the law of uninhibited decay. An initial amount of 0.60 M of compound A decomposes to 0.55 M in 30 minutes. How much of compound A will remain after 2 hours? .42 is the answer I came up for on this part.<BR>\n" );
document.write( "Model:: y = ab^x<BR>\n" );
document.write( "0.55 = 0.6*b^(1/2)<BR>\n" );
document.write( "sqrt(b) = 0.9167<BR>\n" );
document.write( "b = 0.8403<BR>\n" );
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document.write( "Equation:<BR>\n" );
document.write( "y = 0.6*0.8403^x<BR>\n" );
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document.write( "Your Problem<BR>\n" );
document.write( "y = 0.6*(0.8403)^2<BR>\n" );
document.write( "y = 0.4236<BR>\n" );
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document.write( " How long will it take until 0.10 M of compound A remains?<BR>\n" );
document.write( "0.10 = 0.6*0.8403^x<BR>\n" );
document.write( "0.8403^x = 0.167<BR>\n" );
document.write( "x = ln(0.167)/ln(0.8403) = 10.29 hours<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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