Answered: 4. What is the molality (m) of a…

4. What is the molality (m) of a solution prepared by dissolving 78.0 g ethylene glycol, HOCH,CH,OH, in 1500. g of water? Show work.

Chemistry: The Molecular Science

5th Edition

ISBN:9781285199047

Author:John W. Moore, Conrad L. Stanitski

Publisher:John W. Moore, Conrad L. Stanitski

Chapter13: The Chemistry Of Solutes And Solutions

Section: Chapter Questions

Problem 106QRT: Calculate the molality of a solution made by dissolving 115.0 g ethylene glycol, HOCH2CH2OH, in 500....

See similar textbooks

Similar questions

A patient has a “cholesterol count” of 214. Like manyblood-chemistry measurements,this result is measured inunits of milligrams per deciliter (mgdL1). Determine the molar concentration of cholesterol inthis patient’s blood, taking the molar mass of cholesterolto be 386.64gmol1. Estimate the molality of cholesterol in the patient’sblood. If 214 is a typical cholesterol reading among men inthe United States, determine the volume of such bloodrequired to furnish 8.10 g of cholesterol.
The freezing point of a 0.21 m aqueous solution of H2SO4 is -0.796C. (a) What is i? (b) Is the solution made up primarily of (i) H2SO4 molecules only? (ii) H+ and HSO4- ions? (iii) 2H+ and 1SO42- ions?
How do colloids differ from solutions with regard to dispersed particle size and homogeneity?
Sodium chloride (NaCl) is commonly used to melt ice on roads during the winter. Calcium chloride (CaCl2) is sometimes used for this purpose too. Let us compare the effectiveness of equal masses of these two compounds in lowering the freezing point of water, by calculating the freezing point depression of solutions containing 200. g of each salt in 1.00 kg of water. (An advantage of CaCl2 is that it acts more quickly because it is hygroscopic, that is. it absorbs moisture from the air to give a solution and begin the process. A disadvantage is that this compound is more costly.)
Calculate the molality of a solution made by dissolving 115.0 g ethylene glycol, HOCH2CH2OH, in 500. mL water. The density of water at this temperature is 0.978 g/mL. Calculate the molarity of the solution.
The dispersed phase of a certain colloidal dispersion consists of spheres of diameter 1.0 102 nm. (a) What are the volume (V=43r2) and surface area (A = r2) of each sphere? (b) How many spheres are required to give a total volume of 1.0 cm3? What is the total surface area of these spheres in square meters?
Insulin is a hormone responsible for the regulation of glucose levels in the blood. An aqueous solution of insulin has an osmotic pressure of 2.5 mm Hg at 25C. It is prepared by dissolving 0.100 g of insulin in enough water to make 125 mL of solution. What is the molar mass of insulin?
You have read that adding a solute to a solvent can both increase the boiling point and decrease the freezing point. A friend of yours explains it to you like this: The solute and solvent can be like salt in water. The salt gets in the way of freezing in that it blocks the water molecules from joining together. The salt acts like a strong bond holding the water molecules together so that it is harder to boil. What do you say to your friend?
Solutions Introduced directly into the bloodstream have to be isotonic with blood; that is, they must have the same osmotic pressure as blood. An aqueous NaCl solution has to be 0.90% by mass to be isotonic with blood. What is the molarity of the sodium ions in solution? Take the density of the solution to be 1.00 g/mL.
6-111 As noted in Section 6-8C, the amount of external pressure that must be applied to a more concentrated solution to stop the passage of solvent molecules across a semipermeable membrane is known as the osmotic pressure The osmotic pressure obeys a law similar in form to the ideal gas law (discussed in Section 5-4), where Substituting for pressure and solving for osmotic pressures gives the following equation: RT MRT, where M is the concentration or molarity of the solution. (a) Determine the osmotic pressure at 25°C of a 0.0020 M sucrose (C12H22O11) solution. (b) Seawater contains 3.4 g of salts for every liter of solution. Assuming the solute consists entirely of NaCl (and complete dissociation of the NaCI salt), calculate the osmotic pressure of seawater at 25°C. (c) The average osmotic pressure of blood is 7.7 atm at 25°C. What concentration of glucose (C6H12O6) will be isotonic with blood? (d) Lysozyme is an enzyme that breaks bacterial cell walls. A solution containing 0.150 g of this enzyme in 210. mL of solution has an osmotic pressure of 0.953 torr at 25°C. What is the molar mass of lysozyme? (e) The osmotic pressure of an aqueous solution of a certain protein was measured in order to determine the protein's molar mass. The solution contained 3.50 mg of protein dissolved in sufficient water to form 5.00 mL of solution. The osmotic pressure of the solution at 25°C was found to be 1.54 torr. Calculate the molar mass of the protein.
A solution is made by dissolving 0.455 g of PbBr2 in 100 g of H2O at 50C. Based on the data in Table 8-1, should this solution be characterized as a. saturated or unsaturated b. dilute or concentrated
Instead of using NaCl to melt the ice on your sidewalk you decide to use CaCl2. If you add 35.0 g of CaCl2 to 150. g of water, what is the freezing point of the solution? (Assume i = 2.7 for CaCl2.)