Question 1

Weight-volume percentage solutions must be made in 100 mL increments.

Accepted Answer

Weight-volume percentage solutions can be made in any volume, not just 100 mL increments. However, it is important to keep track of the amount of solute being added to ensure proper concentration.

Question 2

The more soluble a substance is,the faster it will dissolve.

Accepted Answer

Solubility and rate of dissolution are related but distinct properties. A substance's solubility indicates how much of it can dissolve in a given amount of solvent at a specific temperature, while the rate of dissolution refers to how quickly it dissolves. Factors like temperature, agitation, and particle size can affect the rate of dissolution without necessarily changing the solubility.

Question 3

Solvents and hydrated ions can usually pass though dialyzing membranes

Accepted Answer

Dialyzing membranes allow small molecules like solvents and hydrated ions to pass through while blocking larger molecules like proteins and other macromolecules. Therefore, solvents and hydrated ions can usually pass through dialyzing membranes.

Question 4

The solubility of a substance can be measured in grams substance dissolved per liter of water.This is the same as expressing solubility in moles per liter.

Accepted Answer

The statement is false. The solubility of a substance in grams per liter does not necessarily correspond to a specific number of moles per liter, as it depends on the molecular weight of the substance. However, for compounds with a known molecular weight or formula, it is possible to convert between solubility in grams per liter and moles per liter.

Question 5

All ionic compounds are soluble in water.

Accepted Answer

Not all ionic compounds are soluble in water. Some ionic compounds, such as silver chloride and lead(II) iodide, are insoluble in water.

Question 6

Oil should be a good solvent for polar compounds.

Accepted Answer

Oil is a nonpolar substance and therefore does not dissolve polar compounds well. Polar solvents such as water or alcohols are better suited for dissolving polar compounds.

Question 7

Emulsions are destroyed by adding salt.

Accepted Answer

Adding salt to an emulsion can cause the droplets of one liquid to coalesce, leading to the separation of the two liquids in the emulsion. This is why salt is often used to "break" emulsions, such as in separating water and oil in salad dressings.

Question 8

Light scattering is an effective way to distinguish between true solutions and colloidal dispersions.

Accepted Answer

This statement is true. Light scattering can be used to analyze the size and concentration of particles in a solution or dispersion, allowing for differentiation between true solutions and colloidal dispersions.

Question 9

Dialysis and osmosis are used for the same purposes.

Accepted Answer

While both processes involve the movement of substances through a semi-permeable membrane, they have different purposes. Dialysis is typically used for the removal of waste products from the blood in individuals with kidney failure, while osmosis is a natural process that occurs in living organisms as a means of regulating the balance of water and solutes.

Question 10

Rock candy (large table sugar crystals)can be produced by allowing a hot,saturated solution of sugar in water to cool off.

Accepted Answer

This is a true statement. When a hot, saturated solution of sugar in water cools off, the excess sugar particles will begin to form crystals around a seed crystal, resulting in the formation of rock candy.

Question 11

Ionic compounds are generally insoluble in non-polar solvents.

Accepted Answer

Ionic compounds have strong electrostatic attractions between their oppositely charged ions which prevent them from dissolving in non-polar solvents that do not have charged particles. Non-polar solvents like oil or grease lack dipole moments and cannot dissolve polar or ionic substances. Therefore, ionic compounds are considered to be insoluble in non-polar solvents.

Question 12

Dialysis can be used to separate solutions from colloids.

Accepted Answer

Dialysis is a process that separates small dissolved ions from large molecules and colloids. It is commonly used to remove waste products and excess fluid from the blood in patients with kidney failure.

Question 13

Attractive forces between solute and solvent molecules are an important factor in solution formation.

Accepted Answer

Attractive forces between solute and solvent molecules help in dissolving the solute in the solvent, which is an essential aspect of solution formation. Without these forces, it would be difficult to create a stable and homogeneous mixture of solute and solvent molecules.

Question 14

The %(w/v)of a solution is defined as:

Accepted Answer

The answer of The %(w/v)of a solution is defined as:...

Question 15

There is a 12 M aqueous HCl solution in the stock room,but a 6 M solution is required for an experiment.Doubling the volume of a 12 M sample with water will produce a 6 M solution.

Accepted Answer

If we double the volume of a 12 M solution by adding an equal volume of water, we will end up with a 6 M solution. This is because the total amount of acid remains the same (12 x V) and is now diluted in twice the volume (2V) of solution. Therefore, the concentration is halved (12 x V / 2V = 6 M).

Question 16

A mixture of sand and water would be an example of a colloidal suspension.

Accepted Answer

A mixture of sand and water is a heterogeneous mixture, not a colloidal suspension, because the sand particles are too large to stay permanently suspended and will settle out over time.

Question 17

Colloids can be stabilized by emulsifying agents.

Accepted Answer

Emulsifying agents can stabilize colloids by preventing the dispersed particles from clumping together and settling out of the mixture.

Question 18

Colloids are considered to be homogenous mixtures.

Accepted Answer

The answer of Colloids are considered to be homogenous mixtures....

Question 19

Putting a celery stick in distilled water results in the uptake of water by the celery.

Accepted Answer

This process is called osmosis, where water moves from a region of higher concentration (distilled water) to a region of lower concentration (inside the celery) through a semi-permeable membrane.

Question 20

The solubility of gases in water increases with increasing temperature.

Accepted Answer

The solubility of gases in water typically decreases with increasing temperature, as higher temperatures give gas molecules more energy to escape from the solution.

Quiz 7: Solutions and Colloids