document.write( "Question 1061097: if a chemist needs a 40% acid solution, how much 50% solution needs to be mixed with 8 liters of a 25% solution to obtain the desired concentration? \n" ); document.write( "
Algebra.Com's Answer #675916 by KMST(5328)\"\" \"About 
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\"x\"= volume of 50% solution needed (in Liters)
\n" ); document.write( "\"8\"= volume of 25% solution used (in Liters)
\n" ); document.write( "\"V\"= volume of the final 40% solution mixture (in Liters)
\n" ); document.write( "\"0.5x\"= amount of acid in \"x\" Liters of 50% solution
\n" ); document.write( "\"0.25%2A8\"= amount of acid in \"8\" Liters of 25% solution
\n" ); document.write( "We need to make it so that
\n" ); document.write( "{{A=0.40V}}}= amount of acid in \"V\" Liters of 40% solution
\n" ); document.write( "We know that
\n" ); document.write( "\"A=0.5x%2B0.25%2A8\"= amount of acid in the final mixture
\n" ); document.write( "We assume that there was no substantial volume change on mixing, so
\n" ); document.write( "\"V=8%2Bx\"= final volume (assumed, in Liters)
\n" ); document.write( "We can solve (the system of the last 3 equations) for \"A\" , \"V\" , and \"x\" ,
\n" ); document.write( "or we can combine the 3 equations into one as
\n" ); document.write( "\"0.40%288%2Bx%29=0.5x%2B0.25%2A8\" and solve for \"x\" .
\n" ); document.write( "Solving:
\n" ); document.write( "\"0.4%288%2Bx%29=0.5x%2B0.25%2A8\"
\n" ); document.write( "\"3.2%2B0.4x=0.5x%2B2.0\"
\n" ); document.write( "\"3.2-2.0=0.5x-0.4x\"
\n" ); document.write( "\"1.2=0.1x\"
\n" ); document.write( "\"x=1.2%2F0.1\"
\n" ); document.write( "\"x=12\" .
\n" ); document.write( "We need to mix \"highlight%2812%29\" Liters of 50% solution with the 8 Liters of 25% solution to obtain the desired concentration.
\n" ); document.write( "Bonus answer:
\n" ); document.write( "We expect to end up with a final volume (in liters) of
\n" ); document.write( "\"V=8%2B12=20\" .
\n" ); document.write( "
\n" ); document.write( "NOTEs:
\n" ); document.write( "When you mix to solutions the final volume is not exactly the sum of the volumes mixed, but in many cases it will be close enough for your purposes
\n" ); document.write( "
\n" ); document.write( "\"Acid\" does not identify any chemical, or mixture of compounds.
\n" ); document.write( "In chemistry, it identify a very broad class of chemical compounds. Exanples: ascorbic acid (also known as vitamin C), acetylsalicylic (also known as aspirin), acetic acid (the chemical compound present, along with a lot of water, in vinegar), hydrochloric acid (a solution of the gas hydrogen chloride in water, at a concentration of about 36 grams gas per 100 grams of solution), sulfuric acid (the chemical with formula \"H%5B2%5D\"\"SO%5B4%5D\", or a solution usually containing 98 grams of that chemical per 100 grams of solution)
\n" ); document.write( "
\n" ); document.write( "In the language on non-chemists, it could mean a chemical that can cause burns and dissolve certain things, or LSD, or who knows what.
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