9. Solutions

What volume in (µL) of 0.125 M HBr contains 0.170 moles HBr?

Hypernatremia is a medical condition where a patient has high levels of sodium in their blood, and is the result of the body containing too little water. A patient has a measured sodium level of 165 mM. If 30.0 mL of their blood were drawn, what mass (in ng) of sodium would be present?

2.64 grams of an unknown compound was dissolved in water to yield 150 mL of solution. The concentration of the solution was 0.075 M. What was the molecular weight of the substance?

A solution with a final volume of 750.0 mL was prepared by dissolving 30.00 mL of benzene (C₆H₆, density = 0.8787 g/mL) in dichloromethane. Calculate the molarity of benzene in the solution.

The concentration of cholesterol (C₂₇H₄₆O) in blood is approximately 5.0 mM. How many grams of cholesterol are in 250 mL of blood?

If you had only 23 g of KOH remaining in a bottle, how many milliliters of 10.0% (m/v) solution could you prepare? How many milliliters of 0.25 M solution?

Sodium thiosulfate (Na₂S₂O₃) the major component in photographic fixer solution, reacts with silver bromide to dissolve it according to the following reaction:

AgBr(s) + 2 Na₂S₂O₃(aq) → Na₃Ag(S₂O₃)₂(aq) + NaBr(aq)

b. How many mL of 0.02 M Na₂S₂O₃ contain this number of moles?

In a laboratory experiment, a 10.0-mL sample of NaCl solution is poured into an evaporating dish with a mass of 24.10 g. The combined mass of the evaporating dish and NaCl solution is 36.15 g. After heating, the evaporating dish and dry NaCl have a combined mass of 25.50 g.

b. What is the molarity (M) of the NaCl solution?