Basic lab calculations (milli and micro)
Prefix Symbol Meaning deci d 101 centi c 102 milli m 103 micro µ or mc 106 nano n 109 pico p 1012 femto f 1015 atto a 1018 Problem: You need to supplement the diet of a mouse with zinc. You have a solution of zinc chloride which has a concentration of 100 µg, ml. A mouse eats 5g of food per day. How much of this solution would you need to add to 100 g of laboratory animal food to supplement the mouse with 25 µg of zinc chloride per day А) 5 ml В) 500 ml С) 0. 25 ml D) 0. 05 ml E) 0. 5 ml lets say you need 6. 0 mL of 2. 0 M HCl, but you only have 3. 0 M HCl You could do this in different orders depending on how you like to break down these sort of questions. If we start with the food, 5g of food, day 100g total therefore we need 20 days work of ZnCl2. 20 days x 25 µg per day 500 µg. Our stock is at 100 µg, ml therefore we need 5 ml. The other way would be to say 25 µg is 0. 25 ml of the stock x 20 days 5 ml
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