± Molarity The The chemical 5-amino-2,3-dihydro-1,4-phthalazinedione, better kno
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± Molarity The The chemical 5-amino-2,3-dihydro-1,4-phthalazinedione, better known as luminol, is used by forensic scientists in analyzing crime scenes for the presence of washed-away blood. Luminol is so sensitive that it can detect blood that has been diluted 10,000 times. A basic solution of luminol is often sprayed onto surfaces that are suspected of containing minute amounts of blood. Luminol has a molecular weight of 177 g/moil. Part A The forensic technician at a crime scene has just prepared a luminol stock solution by adding 17.0 g of luminol into a total volume of 75.0 mL of H2O What is the molarity of the stock solution of lumino? Express your answer with the appropriate units You did not open hints for this part ANSWER: molarity of luminol solution 0.96 moles Incorrect; Try Again; 4 attempts remaining Part B Before investigating the scene, the technician must dilute the luminol solution to a concentration of 6.00x102 M. The diluted solution is then placed in a spray bottle for application on the desired surfaces. How many moles of luminol are present in 2.00 L of the diluted spray? Express your answer with the appropriate units. You did not open hints for this part. ANSWER: moles of luminol = Part C This question will be shown after you complete previous question(s)Explanation / Answer
Part A:
Molarity (M) = moles/volume = (mass/molar mass)/ volume
= (17.0 g/177 g/mol) /75.0 mL) = 0.0960 mol/0.0750 L
= 1.28 M
Part B;
Moles = molarity x volume = 6.00x10-2 M x 2.0 L = 0.120 mol
Part D:
Molarity of New solution = (molarity of stock solutiom x volume of stock solution)/ volume of new solution
= (6.07 M x 423 mL) / (423 +115) mL
= 4.77 M
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