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Molarity

#### Q. When 4.36 g of sodium hydroxide are added to 125 mL of 3.80 × 10−1 M HCl, what is the concentration, in M, of OH− in the resulting solution? You may assume the total volume of the final solution is 130 mL.

Solved • Apr 4, 2020

Molarity

#### Q. Calculate the molarity of a solution made by dissolving 0.150 mol m o l Na2SO4 N a 2 S O 4 in enough water to form exactly 760 mL m L of solution.

Solved • Apr 3, 2020

Molarity

#### Q. 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/mol. Before investigating the scene, the technician must dilute the luminol solution to a concentration of 6.00 x 10^-2 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.

Solved • Mar 13, 2020

Molarity

#### Q. 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/mol. The forensic technician at a crime scene has just prepared a luminol stock solution by adding 14.0 g of luminol into a total volume of 75.0 mL of H2O. What is the molarity of the stock solution of luminol? Express your answer with the appropriate units.

Solved • Mar 13, 2020

Molarity

#### Q. Calculate the volume in liters of a 0.068 mol/L potassium dichromate solution that contains 100.0 g of potassium dichromate (K2Cr2O7). Be sure your answer has the correct number of significant digits.

Solved • Mar 26, 2020

Molarity

#### Q. A chemist adds 255.0 mL of a 1.25 mol/L potassium iodide (KI) solution to a reaction flask. Calculate the millimoles of potassium iodide the chemist has added to the flask. Be sure your answer has the correct number of significant digits.

Solved • Mar 26, 2020

Molarity

#### Q. A stock solution is prepared by adding 1.245 g of Mg(OH)2 to 250.0 mL of DI water. Calculate the concentration (in M) of the prepared Mg(OH)2 stock solution?

Solved • Mar 25, 2020