Chemistry Chapter 13: Solutions Quiz

Questions and Answers

Classify each process as an endothermic or exothermic process.

Forming solute-solvent attractions (correct)

Breaking solute-solute attractions (correct)

Breaking solvent-solvent attractions (correct)

All of the above

Determine the enthalpy of solution for a solid with H values for breaking attractions that are one third of the magnitude compared to forming attractions.

Exothermic

Determine the enthalpy of solution for a solid with H values for breaking attractions that are three times the magnitude compared to forming attractions.

Endothermic

Rank the following substances in order from most soluble to least soluble in water: ethane (C2H6), 1-butanol (C4H9OH), table salt (NaCl), propane (C3H8).

Propane (C3H8) Signup and view all the answers

Which solvent will best dissolve wax, a complex mixture mostly made up of CH3-CH2-CH2-CH2-CH2-?

Pentane (CH3CH2CH2CH2CH3) Signup and view all the answers

If you double the partial pressure of a gas over a liquid at constant temperature, there are twice as many gas molecules in the liquid.

False Signup and view all the answers

Where would you expect N2 to fit in a given gas solubility graph compared to CO?

Just below that of CO Signup and view all the answers

Calculate the molality of a 2.350*10^-2 M NaCl solution in water, using 999.4 mL of water.

2.356*10^-2 m Signup and view all the answers

Calculate the mole fraction of a 2.350*10^-2 M NaCl solution in water.

4.241*10^-4 Signup and view all the answers

Calculate the concentration of the salt solution in percent by mass for a 2.350*10^-2 M NaCl solution.

0.1375% Signup and view all the answers

Calculate the concentration of the salt solution in parts per million for a 2.350*10^-2 M NaCl solution.

1375 ppm Signup and view all the answers

If more solvent is added to a solution, doubling the original mass of solvent and then adding more solute to double the original mass of solute, what happens to the molality of the final solution compared to the original molality?

It is unchanged Signup and view all the answers

What is the concentration in units of mole fraction for the solubility of oxygen gas in water at 40 C, which is 1.0 mmol/L?

1.80*10^-5 Signup and view all the answers

Calculate the molarity of calcium in maple syrup if the density is 1.325 g/mL and 100.00 g of syrup contains 67 mg of calcium.

0.022 M Signup and view all the answers

What is the molarity of commercial concentrated aqueous ammonia, which is 28% NH3 by mass and has a density of 0.90 g/mL?

15 M Signup and view all the answers

Arrange the solutions with freezing points: A) -1.45 C, B) -5.96 C, C) -3.04 C.

B, C, A Signup and view all the answers

What is the molal concentration of glucose in a solution that freezes at -3.15 C?

1.69 molal Signup and view all the answers

What is the molal concentration of glucose in a solution that boils at 102.06 C?

4.02 molal Signup and view all the answers

Increasing the temperature raises the osmotic pressure of a solution.

True Signup and view all the answers

Which aqueous solution will have the lowest freezing point?

0.15 m NaCl Signup and view all the answers

List the following aqueous solutions in order of decreasing freezing point: 0.40 m glycerin (C3H8O3), 0.020 m potassium bromide (KBr), 0.030 m phenol (C6H5OH).

0.40 m glycerin, 0.030 m phenol, 0.020 m KBr Signup and view all the answers

Define molality.

Moles of solute/kg of solvent Signup and view all the answers

The density of the solution is needed to calculate the molarity of a 17.5% (by mass) aqueous solution of nitric acid.

True Signup and view all the answers

What is the concentration of Cl- in a solution prepared by dissolving 23.7 g of CaCl2 in 375 g of water, where the density is 1.05 g/mL?

1.12 M Signup and view all the answers

What is the percent by mass of urea in a solution prepared by dissolving 16 g of urea in 52 g of H2O?

24 Signup and view all the answers

What is the mole fraction of urea in a solution prepared by dissolving 16 g of urea in 39 g H2O?

0.11 Signup and view all the answers

Identify the type of interactions involved in each of the following processes taking place during the dissolution of sodium chloride (NaCl) in water.

Solvent-Solvent Interactions = Interactions involving dipole-dipole attractions between the water molecules Solute-Solute Interactions = Interactions between the ions of sodium chloride involving ion-ion attractions Solvent-Solute Interactions = Interactions formed between sodium ions and oxygen atoms of water molecules Signup and view all the answers

Which substances are most likely to undergo dissolution in water?

All of the above Signup and view all the answers

Classify the given compounds according to their strongest solute-solvent interaction when dissolving in water.

C2H5OH and HF are Dipole-Dipole Forces Signup and view all the answers

Which substance is the most soluble in CCl4?

C4H10 Signup and view all the answers

What does the phrase 'like dissolves like' refer to?

Polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes. Signup and view all the answers

When solutions of strong electrolytes in water are formed, the ions are surrounded by water molecules. This interaction is known as what?

Hydration Signup and view all the answers

Which substance is most likely to dissolve in CCl4?

CBr4 Signup and view all the answers

Which of the following liquids is NOT miscible with water?

Hexane (C6H14) Signup and view all the answers

If the methane contained in a saturated solution at 25 C was extracted and placed under STP conditions, what volume would it occupy?

8.74 * 10^-2 L Signup and view all the answers

What explains the variations in solubility for methane, ethane, and ethylene?

Differences in bonding (sigma or pi) between atoms within molecules, and differences in molecular size and shape affect the strength of dispersion forces. Signup and view all the answers

Compared to nitrogen, what makes ethylene more soluble in water?

The larger molecular size of ethylene. Signup and view all the answers

Why is nitric oxide more soluble than nitrogen and oxygen?

Because of its polarity. Signup and view all the answers

What makes nitrogen less soluble compared to oxygen?

Nitrogen's shorter bond length makes it more difficult for water molecules to surround nitrogen molecules. Signup and view all the answers

Explain the high solubility of sulfur dioxide.

Its ability to react with water. Signup and view all the answers

Study Notes

Types of Processes

Exothermic processes involve forming solute-solvent attractions.
Endothermic processes involve breaking solute-solute and solvent-solvent attractions.

Enthalpy of Solution

An exothermic reaction occurs when the breaking of attractions is one-third the magnitude of the forming attractions.
An endothermic reaction occurs when the breaking of attractions is three times the magnitude of the forming attractions, or when all steps involved have approximately equal magnitudes.

Solubility Rankings

Substances ranked from most to least soluble in water: NaCl (table salt), 1-butanol (C4H9OH), propane (C3H8), and ethane (C2H6).

Solvent Compatibility

Pentane (CH3CH2CH2CH2CH3) is best for dissolving wax, which is primarily composed of long-chain hydrocarbons.

Gas Solubility and Pressure

Doubling the partial pressure of a gas above a liquid does not mean there are twice as many gas molecules in the liquid.

Estimated Graph Placement

N2 is expected to fit just below CO on a solubility graph.

Concentration Calculations

A 2.350 x 10^-2 M NaCl solution corresponds to a molality of 2.356 x 10^-2 m.
The mole fraction of NaCl in the solution is 4.241 x 10^-4, and its mass percent is 0.1375%.
The parts per million (ppm) concentration of the NaCl solution is 1375 ppm.

Effects on Molality

Doubling the solvent mass and solute mass keeps the molality of the final solution unchanged.

Concentration Conversion

The solubility of oxygen gas in water at 40°C is equivalent to a mole fraction of 1.80 x 10^-5.

Calcium Molarity and Concentration

Molarity of Ca2+ ions in maple syrup is 0.022 M.
Commercial concentrated ammonia has a molarity of 15 M due to its 28% mass concentration.

Freezing Point Depression

The order of decreasing molal concentration related to freezing points: B (-5.96°C), C (-3.04°C), A (-1.45°C).
For a glucose solution that freezes at -3.15°C, the molal concentration is 1.69 molal.

Boiling Point Elevation

A glucose solution that boils at 102.06°C has a molal concentration of 4.02 molal.

Osmotic Pressure

Increasing the temperature of a solution raises its osmotic pressure.

Freezing Point Comparison

The lowest freezing point among solutions is 0.15 m NaCl.

Solution Freezing Points

Aqueous solutions arranged from highest to lowest freezing point: 0.030 m phenol, 0.020 m potassium bromide, 0.40 m glycerin.

Molality Definition

Molality is defined as moles of solute per kilogram of solvent.

Density and Molarity Calculations

To calculate molarity of a 17.5% nitric acid solution, density information is essential.
The concentration of Cl- in a solution with calcium chloride is computed as 1.12 M.

Percent by Mass and Mole Fraction

The percent by mass of urea in solution is calculated at 24%.
The mole fraction of urea, after dissolution of 16 g in 39 g of H2O, is 0.11.

Dissolution Interactions

Solvent-solvent interactions are characterized by dipole-dipole attractions between water molecules.
Solute-solute interactions involve ion-ion attractions between sodium chloride ions.
Solvent-solute interactions occur between sodium ions and water's oxygen atoms, and between chloride ions and water's hydrogen atoms.

Solubility Prediction

Lithium bromide, sodium iodine, and potassium bromide are likely to dissolve in water.

Solute-Solvent Interactions

Dipole-dipole forces are strongest in ethanol (C2H5OH) and HF.
Ion-dipole forces are observed in salts like CaCl2 and CuSO4.

Solubility in Nonpolar Solvents

C4H10 is most soluble in CCl4.
"Like dissolves like" principle applies where polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes.

Hydration Process

The interaction of ions from strong electrolytes in water is known as hydration.

Miscibility

Hexane (C6H14) is not miscible with water.

Gas Solubility Variations

Variations in solubility of methane, ethane, and ethylene arise from differences in bonding and molecular size.

Comparative Solubility

Ethylene's larger size enhances its water solubility over nitrogen due to increased polarity.

Reactivity with Water

Sulfur dioxide's high solubility arises from its ability to react with water.

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Description

Test your understanding of solutions with this quiz on endothermic and exothermic processes outlined in Chapter 13. Classify processes based on interactions in solutions and calculate the enthalpy of solutions using provided H values. Prepare to deepen your chemistry knowledge!