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Chemistry Textbook

Self-Assessments

 

What is the molality of the solution formed by dissolving 20.0 g of NaCl in water to make a 100. gram solution?

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Bleach is a solution of sodium hypochlorite (NaClO) and water.
The mass percent of a household bleach is 6.1% by mass. What mass of the bleach contains 1.5 g NaClO?

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An instant ice-pack contains a mixture of 125 g of NH4NO3in 275 g of water. What is the mole-fraction of NH4NO3?

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To create the acid solution used in an automobile battery, 583 g of H2SO4is dissolved in 1.50 kg of water. What is the mass percent of sulfuric acid in the acid solution?

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A 50.0 g hand sanitizer solution contains 0.75 g of glycerin (C3H8O3). What is the molarity of glycerin in the hand sanitizer?
The density of the hand sanitizer is 0.85 g/mL

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The concentration of acetic acid (CH3COOH) in a store-bought vinegar is 5.0% by mass. What is the molarity of acetic acid in the vinegar?
The molarity of the vinegar solution is 1.02 g/mL

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A 14.6 M phosphoric acid has a density of 1.685 g/mL. What is the mass percent (m/m%) of the H3PO4 solution?

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The antifreeze in most automobile radiators is a mixture of equal volumes of ethylene glycol (C2H6O2) and water, with a minor amount of other additives to prevent corrosion.
What is the molality of an antifreeze solution that has 0.244 mole fraction of ethylene glycol?

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Commercially available sulfuric acid (H2SO4) has 18.0 M What is the molal concentration of the sulfuric acid. The density of the sulfuric acid is 1.84 g/mL.

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What is the molarity of 2.0 m KI solution that has a density of 1.22 g/mL?

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The solution with the highest concentration of dissolved particles will have the highest _______.

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Which of the following 0.1 m solutions lowers the freezing point of water the most?

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Which of the following solutions will have the lowest freezing point?

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Which of the following solutions will have the lowest boiling point?

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Which of the following solutions is arranged correctly according to decreasing order of vapor pressure?
(I) 0.05 M NaCl
(II)15 M (NH4)2SO4
(III) 0.15 M KBr
(IV) 0.20 M sucrose (C12H22O11)
(V) 0.10 M Al(NO3)3

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CaCl2 is used as a common de-icing agent. If 10.0 g of CaCl2 is dissolved in 85 g of water, What is the freezing point of the resulting solution under normal pressure?
Assume the ideal value of Van’t Hoff factor.

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Assume that sea water is 3.5% NaCl by mass.
What is the boiling point of sea water at normal pressure?

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Calculate the vapor pressure of a solution formed by dissolving 10.0 g of glucose (C6H12O6) in 100.0 g of water at 25o
The vapor pressure of pure water at 25oC is 23.80 mm Hg.

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Codeine, C18H21NO3,is an opioid pain reliever used to treat mild to moderately severe pain.
85 g of codeine is dissolved in 125.5 g of ethanol, C2H5OH. What is the boiling point of the resulting solution?

Boiling point of pure ethanol is 78.37oC.
Molal boiling point elevation constant of ethanol is 1.23 oC/m.

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What is the osmotic pressure at 20oC of a 100.0 mL aqueous solution that contains 1.6 g Na3PO4.

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A solution is prepared by dissolving 2.20 g of a non-electrolytic compound in 20.0 g of water. The boiling point of the solution is 100.98oC at normal pressure. What is the molar mass of the compound?

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2.00 g of some unknown non-electrolyte is added to 75.00 g of benzene and the freezing point reduces from 5.53 oC to 4.90 oC. What is the molar mass of the solute?
Molal freezing point depression constant of benzene is 5.12oC/m.

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A salt is known to be an alkali metal fluoride. A quick approximate determination of freezing point indicates that 4.0 g of the salt dissolved in 100 g of water produces a solution that freezes at about −1.4 °C. Assuming ideal solution behavior, what is the molar mass of the salt?

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The Hemoglobin molecule carries oxygen in human blood. A water solution that contains 0.263 g of hemoglobin (Hb) in 10.0 mL of solution has an osmotic pressure of 7.51 torr at 25oC. What is the molar mass of the hemoglobin?

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The sugar galactose contains 40.0% C, 6.7% H, and 53.3% O by mass. A solution of 11.7 g of galactose in 325 g of ethanol has a boiling point of 78.59 °C. The boiling point of ethanol is 78.35 °C, and Kbfor ethanol is 1.20 °C/m. Assuming ideal solution behavior, what is the molecular formula of galactose?

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