# Osmosis- Simple Quiz

10 Questions

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Why does the concentration of a solute cause the movement of water through osmosis? Water is unusual in that it can cross a non-polar membrane but also react and form solutions with ions and polar molecules that cannot cross the same membrane. When water molecules react with a solute they are no longer free to cross the membrane. The more solute, the fewer molecules left that are free to diffuse across the membrane. Therefore a highly concentrated solution (one with lots of solute) has a low effective concentration of water. Therefore water will tend to diffuse across a membrane from areas of low solute concentration to areas of high solute concentration – until the concentration of the solution is equal on both sides. This is only true if the solute cannot cross the membrane.

Related Topics
• 1.
When a membrane that is permeable to both a solute and water separates water with a high osmolarity from water with a low osmolarity...
• A.

The water will only move through the membrane in one direction while the solute will move through the membrane in the other.

• B.

The solute will pass through the membrane in both directions until equilibrium is reached on both sides of the membrane for the solute.

• C.

Both the water and the solute will pass through the membrane in both directions until equilibrium is reached on both sides of the membrane for both water and the solute.

• D.

The motion of the molecules of both the solute and water will cease when equilibrium is reached.

• E.

None of the above

• 2.
• A.

The water will diffuse through the membrane until there is an equal volume of solute on both sides.

• B.

The water will diffuse through the membrane until there is an equal volume of water on both sides.

• C.

The water will diffuse through the membrane until there is an equal concentration of water on both sides.

• D.

The water will diffuse through the membrane until there is an equal concentration of solute on both sides.

• E.

The water will diffuse through the membrane until there is an equal concentration of solute and water on both sides.

• 3.
Water is more concentrated in...
• A.

the solution on the side of the membrane with the least solute.

• B.

The solution on the side of the membrane with the most solute.

• C.

The solution on the one side of the membrane that has reached equilibrium.

• D.

The solution on either side of the membrane that has reached equilibrium.

• E.

The solution on neither side of the membrane due to the constant motion of the molecules.

• 4.
Water molecules will no longer pass through the semipermeable membrane once equilibrium is reached.
• A.

True

• B.

False

• 5.
Osmosis can be described as both the diffusion of a liquid from an area of high concentration of that liquid to an area of a low concentration of that liquid, and, as the diffusion of a liquid from a low concentration of solutes to an area of high concentration of solutes.
• A.

True

• B.

False

• 6.
Osmosis is best defined as the movement of
• A.

Molecules from an area of high concentration to an area of lower concentration

• B.

Molecules from an area of low concentration to an area of higher concentration.

• C.

Water molecules across a membrane from an area of low water to an area of higher concentration.

• D.

Water molecules across a membrane from an area of high water concentration to an area of lower concentration.

• E.

Water molecules inside a container.

• 7.
Which of the following will pass through a cell membrane most easily?
• A.

small polar molecules

• B.

Small nonpolar molecules

• C.

Large polar molecules

• D.

Large nonpolar molecules

• E.

Large neutral molecules

• 8.
A red blood cell placed in a hypertonic medium will
• A.

Expand.

• B.

Burst.

• C.

Shrink.

• D.

Have no change in shape.

• E.

Become a white blood cell.

• 9.
A 5% urea solution is hypotonic to a 10% urea solution.
• A.

True

• B.

False

• 10.
If a cell is placed in an isotonic medium, there will be no net movement of water.
• A.

True

• B.

False