# Chemistry

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

1. 👍
2. 👎
3. 👁
1. 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.

1. 👍
2. 👎
2. # of moles of solute
Molarity = --------------------
Liters of solution

1. 👍
2. 👎
3. 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.

1. 👍
2. 👎
4. 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.

1. 👍
2. 👎
5. 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

1. 👍
2. 👎
6. see above.

1. 👍
2. 👎
7. 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.

1. 👍
2. 👎
8. 144 ml

1. 👍
2. 👎
9. 114

1. 👍
2. 👎
10. Steiger nei von streiger sneiten mehr ruellen toft don wulka

1. 👍
2. 👎
11. 159

1. 👍
2. 👎

## Similar Questions

1. ### Science

Why do scientists use models? a: Scientists use models to learn about things that are too small, too large, or too complex to observe directly. < b:Scientists use models because doing so is always part of the scientific method.

2. ### CHEM

Help on part "c": The forensic technician at a crime scene has just prepared a luminol stock solution by adding 19.0g of luminol into a total volume of 75.0mL of H2O. a)What is the molarity of the stock solution of luminol? anwer

Individuals can use different criteria to analyze artwork. What would be an example of inappropriate criteria for analyzing this piece of art. A- Capturing daily scenes B- capturing likeness to the individuals C- Creating an image

4. ### science

All biomolecules are made up of the elements carbon, hydrogen, nitrogen, oxygen, and sulfur. carbon, hydrogen, nitrogen, and oxygen. carbon, hydrogen, oxygen, and sulfur. carbon, hydrogen, and oxygen.*** Nucleic acids are the

1. ### Chem 1

The forensic technician at a crime scene has just prepared a luminol stock solution by adding 15.0g of luminol into a total volume of 75.0 \rm mL of \rm H_2O. What is the molarity of the stock solution of luminol? 1.13M Before

2. ### Biology

Which statement is true? Amino acids do not need to be assembled in a particular order. tRNA is attached to specific proteins in the cell’s cytoplasm.** Amino acids form a chain via carbon bonds. The human body uses 20 amino

3. ### Chemistry!

Before investigating the scene, the technician must dilute the luminol solution to a concentration of 6.00×10−2 M. The diluted solution is then placed in a spray bottle for application on the desired surfaces. How many moles of

4. ### college

he forensic technician at a crime scene has just prepared a luminol stock solution by adding 12.0 g of luminol into a total volume of 75.0 \rm mL of \rm H_2O.

1. ### Biochemistry Unit Test

Questions: 1.What is the maximum number of electrons carbon’s outer shell can hold? 2.What is the definition of a hydrocarbon? 3.What do amino acids, fatty acids, and sugars (monosaccharides) have in common? 4.What makes amino

2. ### Chemistry

A. The forensic technician at a crime scene has just prepared a luminol stock solution by adding 13.0 g of luminol into a total volume of 75.0 mL of H2O. -What is the molarity of the stock solution of luminol? B. Before

3. ### biology

Which statement is true?(1 point) The human body uses 21 amino acids to form all types of proteins.** Amino acids do not need to be assembled in a particular order. tRNA is attached to specific proteins in the cell’s cytoplasm.

4. ### chemistry

One method of analyzing amino acids is the van Slyke method. The characteristic amino groups (−NH2) in protein material are allowed to react with nitrous acid, HNO2, to form N2 gas. From the volume of the gas, the amount of