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
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
11 answers
# of moles of solute
Molarity = --------------------
Liters of solution
Molarity = --------------------
Liters of solution
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.
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.
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.
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.
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
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
see above.
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.
144 ml
114
Steiger nei von streiger sneiten mehr ruellen toft don wulka
159
4 answers