Question

Microbiologists use acid-alcohol when performing a cell stain of the pathogen Mycobacterium tuberculosis. A common recipe is to make 3%(wt/vol) HCl in ethanol. HC has a formula weight of 36.46 grams per mole. If the stock solution of HCl is 1 moles per 1000 ml, how many mL of HCI need to be added to achieve a final volume of 100 mL of acid alcohol solution? Report your answer to two decimal places. Algebra can be used to solve this problem! In this context, the percentages act as concentrations. Therefore, it is possible to use m;V= mV2 and use the percentages as the concentration values. We can solve for m, by converting the molarity of HCl into a percentage using its formula weight 36.46 g HCI m, Mol HCI x 100 = %HCI mol HCI 1000 mL X Then substitute this value of my into the equation mivi = m2V2 and solve for vi Vi m2V2 mi (3%) (v2) 36.46 g HCI m, Mol HCI 1 mol HCI 1000 mL 4) (100)