Quiz

What are the particle size of colloids?

1nm-1000nm

A molecular compound is what?

A nonelectrolyte

Why does a salt solution conduct electricity?

A salt conducts electricity because dissolved ions in solution can move charge from one point in the solution to another. Salt is ionic

Why does a sugar-water solution not conduct electricity?

A sugar solution does not conduct electricity because there are no charged particles dissolved in solution. Sugar is nonpolar

How would you make a saturated solution of sugar in water a supersaturated solution of sodium acetate in water?

Add sodium acetate to hot water until saturated. Set the solution aside until it cools to room temperature. Once it cools, it will be supersaturated.

An ionic compound and acid/base is what?

An electrolyte

How do you separate suspensions?

Can you filtration, the particles will settle

Particles are intermediate in size between those of a solutions and those of a suspension?

Colloid

Particle that are intermediate in size between those in solutions and suspensions form mixtures known as what?

Colloids

Explain how you would prepare a saturated solution of sugar in water.

Continually add sugar to water until undissolved grains remain as the bottom of the container. This is a saturated solution of sugar and water.

When a solute molecule is solvated, is energy released or absorbed?

Depending on the solute and solvent energy can be released or absorbed. Refer to figure 2.13 for examples of each.

The rapid escape of a gas from a liquid in which it is dissolved is known as what?

Effervescence

What are substances called whose water solutions conduct electricity?

Electrolytes

The net amount of energy absorbed as heat by the solution when a specific amount of solute dissolved in a solvent is the what?

Enthalpy of solution

Explain why ethanol will dissolve in water and carbon tetrachloride will not.

Ethanol and water are polar molecules. The negatively charged region of the ethanol molecule is attracted to the positively charged region of the water molecules, and vice versa. Carbon tetrachloride is nonpolar and will not form a strong enough attraction to water molecules to dissolve.

The solubility of a gas in a liquid is directly proportional to the partial pressure of that gas on the surface of the liquid...

Henry's law

The solution process with water as the solvent is referred to as what?

Hydration

Why does ice float? Why is this phenomenon important to living things?

Ice floats because it is less dense than liquid water. Ice is less dense than liquid water because the regular hydrogen pattern in ice leads to an open structure with significant empty space in between molecules. This phenomenon is important for aquatic life, during the winter when a lake freezes less dense ice forms only on the surface. The solid top layer insulated the liquid beneath it, preventing a total freeze, which would kill most living things in the lake.

Describe what might be the result if water could freeze at a higher temperature. How might this affect chemical and biological systems that contain water?

If water could freeze at a higher temperature, this could lead to lakes and even oceans becoming totally frozen much more quickly. It also might inhibit the water cycle that moves water around the planet. Water freezing at a higher temperature also could cause fluids in the body to freeze.

Liquids that are not soluble in each other are what?

Immiscible

What is the Tyndall effect?

It scatters light

A "fizz saver" pumps air under pressure into a soda bottle to keep gas from escaping. Will this keep CO2 in the soda bottle? Explain your answer.

It will not keep carbon dioxide gas from escaping from the solution. It is the partial pressure of the same gas both above and within the solution that keeps that gas in solution. Increased pressure of only air will have no effect on the solubility of carbon dioxide.

What is the particle size of suspensions?

Largest particle size (1000 nm or larger)

Describe the arrangement of molecules in liquid water and in ice.

Liquid water and solid water (ice) have molecules with hydrogen bonding, an intermolecular force. Liquid water had 4 to 8 molecules per group. In solid water all the molecules are arranged in a hexagonal shape.

Liquids that dissolve freely in one another in any proportion are said to be what?

Miscible

What is an example of a suspension?

Oil spill in water

Is orange juice a heterogeneous or homogeneous mixture?

Orange juice is heterogeneous; orange juice settles upon sitting and is a suspension.

A solution that contains the maximum amount of dissolved solute is described as a what?

Saturated solution

What is the particle size of a solution?

Smallest size (0.01 nm to 1 nm)

What are examples of colloids?

Smog, paint, mud, gelatin, milk, smoke, butter

The what of a substance is the amount of that substance required to form a saturated solution with a specific amount of solvent at a specified temperature?

Solubility

A homogenous mixture of two or more substances uniformly dispersed throughout a single phase

Solution

What is the physical state in which the opposing processes of dissolution and crystallization of a solute at equal rates?

Solution equilibrium

A solute particle that is surrounded by solvent molecules is said to be what?

Solvated

Name the solute and solvent in 14-karat gold

Solvent: gold Solute: silver, copper

Name the solute and solvent in carbonate (sparkling) water

Solvent: water Solute: carbon dioxide

Name the solute and solvent in corn syrup

Solvent: water Solute: sugar

Describe one way to prove that a mixture of sugar and water is a solution and that a mixture of sand and water is not a solution.

Sugar in water will not settle and cannot be separated by filtration. The only way to separate the sugar from the water is evaporation. Sand in water will separate upon standing (settle) and can also be filtered.

What is a solution that contains more dissolved solute than a saturated solution contains under the same conditions?

Supersaturated solution

If the particles in a solvent are so large that they settle out unless the mixture is constantly stirred or agitated, the mixture is called a what?

Suspension

Particles that settle out unless the mixture is constantly stirred

Suspension

Is tap water a homogeneous or heterogeneous mixture?

Tap water is homogeneous; the water and dissolved ions are a solution

Why would you expect a packet of sugar to dissolve faster in hot tea than in iced tea?

The particles in hot tea move faster than in iced tea. Therefore, there are more collisions between the tea and sugar molecules at the surface of the sugar grains, and sugar molecules leave the surface of the grains faster in hot tea than in cold tea.

How is the structure of water responsible for some of water's unique characteristics?

The structure of water allows for hydrogen bonding, resulting in the formation of molecular groups that produce a high boiling point.

If a warm bottle of soda and a cold bottle of soda are opened, which will effervesce more and why?

The warm bottle will effervesce more because the gas will be less soluble in the warmer bottle of soda.

How can colloids be separated?

They cannot be separated by filtration and cannot be separated by settling

How can solutions be separated?

They cannot be separated by filtration and cannot be separated to settling

You get a small amount of lubricating oil on your clothing. Which would work better to remove the oil-water or toluene? Explain.

Toluene- Oil and toluene are both nonpolar and will dissolve in each other. Water is polar and will not dissolve oil.

A solution that contains less solute than a saturated solution under the existing condition is a what?

Unsaturated solution

If you allow a container of sea water to sit in the sun, the liquid level gets lower and lower, and finally crystals appear. What is happening?

Water (the solvent) is evaporating, leaving the dissolved salts (solutes) as solids.

Why is a water molecule polar?

Water is a polar molecule due to its bent (angular) shape of the molecule.

If pressure is decreased then gas solubility...

Will decrease (rapid bubbling)

If temp is increased then gas solubility....

Will decrease (rapid bubbling)

If temp is decreased then gas solubility...

Will increase ( bubbles)

If pressure is increased then gas solubility...

Will increase (bubbling stops)