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Chemistry, 23.04.2020 17:53 ssollers

In lab, scientists often use percentages to describe concentration. When making a solution, percentage can be expressed as weight over volume (wt/vol) or as weight over weight (wt/wt). When expressing things as %(wt/wt) it usually assumed that 1 mL of water = 1 gram of water. This is similar to assuming molarity (mol/L) equals molality (mol/kg)In lab, 70%(wt/vol) ethanol is frequently used to sanitize the lab bench or research tools such as forceps. In order to produce a final volume of 150 mL of 70%(wt/vol) ethanol, how many mL of 96%(wt/vol) ethanol would you need to add?The percentages can be treated as a concentration. A solution that is 70% ethanol is 70 g of ethanol and 30 mL of water, or 70 g Ethanol out of 100 mL of solution. Therefore, it is possible to use m1v1 = m2v2 and use the percentages as the concentration values. Report your answer rounded to two decimal places

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In lab, scientists often use percentages to describe concentration. When making a solution, percenta...
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