Asked by Danielle

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 177g/mol


The forensic technician at a crime scene has just prepared a luminol stock solution by adding 14.0 of luminol into a total volume of 75.0 of .

1. What is the molarity of the stock solution of luminol?
ANSWER:molarity of luminol solution =1.05
2.Before investigating the scene, the technician must dilute the luminol solution to a concentration of 6.00×10−2 . 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?
ANSWER: moles of luminol =0.120

3.What volume of the stock solution (Part A) would contain the number of moles present in the diluted solution (Part B)?

Answer: needs to be in mL and i cant figure it out. Can someone please help



Answered by Danielle
The density of a 22.0% by mass ethylene glycol (C2H6O2) solution in water is 1.03 g/mL. Find the molarity of the solution.

Answer in M
Answered by linell
# of moles of solute
Molarity = --------------------
Liters of solution
Answered by DrBob222
I'm confused by the luminol question.
First, 14 g in 75.0 what unit. If that is 75 mL, then the answer of 1.05 M is correct.
Second, 6.00 x 10^-2 what? If that is molar, then no matter how it was diluted, your answer of 0.120 M is correct.
Third, how much volume? Is that the 2 L of solution from part B? If so then 1.05M x ? L = = 0.120 moles and solve for liters and convert to mL. If it isn't 2L, then supply the correct value.
Answered by DrBob222
For the ethylene glycol solution.
The density is 1.03 g/mL. How much will a liter of the solution weigh? That will be
1.03 g/mL x 1000 mL = 1030 grams.
How much of that is ethylene glycol. 22%? So how much with the ethylene glycol weigh? That will be 1030 x 0.22 = ??
How many moles is that?
??/molar mass ethylene glycol = xx
molarity = xxmoles/L solution.
Answered by Chemistry
Sorry about that

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 177g/mol


The forensic technician at a crime scene has just prepared a luminol stock solution by adding 14.0 of luminol into a total volume of 75.0 mL of H2O.

1. What is the molarity of the stock solution of luminol?
ANSWER:molarity of luminol solution =1.05 M

2.Before investigating the scene, the technician must dilute the luminol solution to a concentration of 6.00×10−2 . 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?
ANSWER: moles of luminol =0.120

3.What volume of the stock solution (Part A) would contain the number of moles present in the diluted solution (Part B)?

Answer: needs to be in mL and i cant figure it out. Can someone please help
Answered by DrBob222
see above.
Answered by Brent
It pretty simply really. All you have to do is use the same formula that you would to convert the weight of a snail into light years.
Answered by jose paulo
144 ml
Answered by M.T.
114
Answered by Thomas
Steiger nei von streiger sneiten mehr ruellen toft don wulka
Answered by MC
159
There are no AI answers yet. The ability to request AI answers is coming soon!