ADV Unit 8 Notes

Multiple Choice

Let's review. See if you can remember. Is this a pure substance (element or compound), a heterogeneous mixture or homogeneous mixture?

Powdered Laundry Detergent (with blue and white crystals)

• homogeneous mixture
• element
• compound
• heterogeneous mixture

Multiple Choice

Kool Aid

(sugar + water + flavorings)

C₁₂H₂₂O₁₁ + H₂O

• heterogeneous mixture

• homogeneous mixture

• pure substance

• element

Multiple Choice

Solutions, suspensions, and colloids are all...

• types of solutions
• types of compounds
• types of mixtures
• types of elements

Multiple Choice

What is the major distinction between suspensions and colloids?

• Colloids have larger particles than suspensions

• Suspensions settle out while colloids don't

• Colloids contain atoms, ions, or molecules while suspensions contain mid-sized particles

• Colloids are heterogeneous while suspensions are homogeneous

Multiple Choice

Which of the following is an example of a colloid?

• Old Spice Fiji deodorant

• Italian dressing

• Coffee

• Milk

Multiple Choice

What is the Tyndall effect used to distinguish between?

• Colloids and compounds

• Solutions and suspensions

• Solutions and compounds

• Colloids and suspensions

Multiple Choice

What is the particle size in a colloid compared to a solution?

• The same

• Depends on the specific mixture

• Smaller

• Larger

Multiple Choice

A snow globe would be an example of a __________________.

• colloid

• solution

• suspension

Multiple Choice

Which mixture has intermediate sized particles?

• Colloids
• Emulsions
• Suspensions
• Solutions

Multiple Choice

The erratic motion of colloid particles is:

• Thermal agitation
• Brownian motion
• Electrostatic repulsion
• Viscous drag

Multiple Choice

A ______________ is one that does not have a uniform composition.

• heterogeneous mixture

• homogenous mixture

• pure substance

Multiple Choice

A _________________ mixture is one where the substances are evenly spread throughout.

• heterogeneous

• homogeneous

• pure substance

Multiple Choice

_______________ are mixtures in which its particles are too big to stay mixed without being stirred or shaken.

• Solutions

• Colloids

• Suspensions

Multiple Choice

A type of mixture where the particles are larger than those in a solution but not heavy enough to settle out.

• Homogeneous mixture

• Colloid

• Suspension

• Compound

Multiple Choice

The beaker on the left would be a _______ (both have been recently stirred)

• Solution

• Suspension

• Colloid

• Impossible to tell

Multiple Choice

If you shine a light into a liquid and the light is scattered, this is called ________

• the tyndall effect

• suspension

• colloid

• a suspension or colloid

Multiple Choice

What is the percent by mass of a solution made by dissolving 20.0 g of NaCl into 180.0 g of water?

• 10.0 %

• 11.1 %

• 80.0 %

• 20.0 %

Multiple Choice

What is the molarity of 0.068 mol of NaCl in 3.8 L of solution?

• 0.018 M

• 0.0011 M

• 1.052 M

• 0.062 M

Multiple Choice

50 ml of a 1 M solution is diluted until the final volume is 80ml. How much water was added?

• 50 ml

• 1.3 ml

• 30 ml

• 130 ml

Multiple Choice

The units "M" can also be written as:

• mol/L

• moles

• g/L

• g/mol

Multiple Choice

A saline solution with a mass of 355 g has 36.5 g of NaCl dissolved in it. What is the percent by mass of NaCl in the solution?

• 20.00%
• 10.3%

• 15.75%
• 5.15%

Multiple Choice

A dextrose (also called D-glucose, C₆H₁₂O₆) solution with a mass of 2.00 × 10² g has 15.8 g of dextrose dissolved in it. What is the mass/mass percent concentration of the solution?

• 5.2%
• 7.90%

• 10.0%
• 12.5%

Multiple Choice

What is the amount (in g) of hydrogen peroxide (H₂O₂) needed to make a 6.00 kg, 3.00 % (by mass) H₂O₂ solution?

*pay attention to the units!

• 150 g
• 200 g
• 120 g
• 180 g

Multiple Choice

Calculate the percent by volume concentration of a solution made by mixing 25 mL of ethanol with enough water to produce a total volume of 200 mL of solution.

• 12.5%
• 10%
• 15%
• 20%

Multiple Choice

1. Calculate the molarity of a solution with 0.444 mol of CoCl₂ in 0.654 L of solution.

• 0.679 M
• 0.600 M
• 0.800 M
• 0.500 M

Multiple Choice

You have a 2.0 M stock solution of hydrochloric acid (HCl). How many milliliters of this stock solution do you need to take to prepare 250 mL of a 0.1 M HCl solution?

• 5 mL
• 12.5 mL
• 50 mL
• 20 mL

Multiple Choice

What phrase summarizes the general rule for solubility of substances?

• Opposites dissolve opposites

• Like dissolves like

• Charged dissolves neutral

• Soluble dissolves insoluble

Multiple Choice

Why is gypsum considered insoluble in water despite being an ionic compound?

• It has a non-polar structure.

• Its attractive forces are too weak.

• It forms covalent bonds instead of ionic bonds.

• Its ions' attractive forces are stronger than the water’s pull.

Multiple Choice

Which of the following will not dissolve in water?

• Salt (NaCl)

• Vinegar (HC₂H₃O₂)

• Oil
• Sugar

Multiple Choice

Which of the following will NOT help a solute dissolve faster in a solvent?

• Increasing temperature

• Increasing surface area

• Agitating the solution

• Decreasing pressure

Multiple Choice

Why is oil immiscible in water?

• Oil contains water molecules that dissolve in it.
• Oil is heavier than water, causing it to sink.
• Oil is a gas at room temperature, making it mix with water.
• Oil is immiscible in water because it is non-polar and water is polar.

Multiple Choice

Which substance will be unsaturated if 10 grams of it is dissolved in 100 grams of water at 50 degrees Celsius?

• KCl
• CaCl₂

• KNO₃

• Ce₂(SO₄)₃

Multiple Choice

If 0.50 g of a gas at 3.5 atm of pressure dissolves in 1.0 L of water at 25°C, how much will dissolve in 1.0 L of water at 1.2 atm of pressure and the same temperature?

• 0.17 g
• 0.50 g
• 0.10 g
• 0.25 g

Multiple Choice

A solution is prepared by dissolving sucrose (C₁₂H₂₂O₁₁C), a non-electrolyte, in water. The molality (m) of the solution is 2.50 mol/kg. Sucrose does not dissociate in water (i=1). The boiling point elevation constant (K_b​) for water is 0.512 °C·kg/mol.

2. Calculate the boiling point elevation (ΔT_b​). If the normal boiling point of water is 100.0 °C, what is the boiling point of the solution?

• 100.75 °C
• 102.50 °C
• 101.28 °C
• 99.75 °C

Multiple Choice

Calcium chloride (CaCl₂​) is commonly used as a de-icing agent. A solution is prepared by dissolving CaCl₂​ in water, resulting in a solution with a molality (m) of 1.20 mol/kg. Calcium chloride dissociates into three ions (Ca²⁺ and two Cl⁻), so i=3. The freezing point depression constant (K_f) for water is 1.86 °C·mol/kg, and the normal freezing point of water is 0.0 °C.

1. Calculate the freezing point depression (ΔT_f​) and determine the freezing point of the solution.

• -2.5 °C
• -6.70 °C

• -10.0 °C
• 0.0 °C

Multiple Choice

Which type of mixture contains particles that will NOT settle out and have intermediate-sized particles?

• Suspension

• Colloid

• Solution

• Supersaturated solution

Multiple Choice

What is the most common solvent among liquid solutions?

• Water

• Methanol

• Carbon dioxide

• Oil

Multiple Choice

In Henry's Law, the solubility of a gas in a liquid is directly proportional to which factor?

• Molar mass of the gas

• Pressure of the gas

• Temperature of the liquid

• Volume of the gas

Multiple Choice

What happens to the solubility of gases as temperature increases?

• It increases.

• It decreases.

• It remains constant.

• It depends on the type of gas.

Multiple Choice

Which colligative property explains why salt is used on icy roads?

• Freezing point depression

• Density increase

• Melting point elevation

• Vapor pressure lowering