document.write( "Question 941109: rubbing alcohol is typically diluted with water to 70% strength. if you need 2.8 oz of 45% rubbing alcohol, how many ounces of 70% rubbing alcohol and how much water should you combine. I know the formula is a.c = q but when sitting up the equation i am very confused. Please help! Thank you in advance. \n" ); document.write( "

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rubbing alcohol is typically diluted with water to 70% strength. if you need 2.8 oz of 45% rubbing alcohol, how many ounces of 70% rubbing alcohol and how much water should you combine. I know the formula is a.c = q but when sitting up the equation i am very confused. Please help! Thank you in advance.
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document.write( "Water + water = water
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document.write( "Let amount of water to mix, be W
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document.write( "The 70% alcohol mixture contains 70% alcohol and 30% water
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document.write( "Amount of mixture before water is added: 2.8 - W
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document.write( "The resulting 45% alcohol mixture will contain 45% alcohol and 55% water
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document.write( "Therefore, we get: .3(2.8 - W) + W = .55(2.8)
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document.write( ".84 - .3W + W = 1.54
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document.write( "- .3W + W = 1.54 - .84
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document.write( ".7W = .7
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document.write( "W, or amount of water to add = , or  oz
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document.write( "You should be able to calculate the amount of alcohol in the mixture. \n" );
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