Osmosis, Solutes, and Solvents

[Soaring Crane]

Are these correct?

1) The rubbing alcohol sold in drug stores often is composed of 70% isopropyl alcohol and 30% water. In this solution

a.both water and isopropyl alcohol are solvents.

b.isopropyl alcohol is the solvent.

c.water is the solvent.

d.neither water nor isopropyl alcohol is a solvent.


2) Which of the following does not affect the solubility of a solute in a given solvent?

a.polarity of the solute

b.temperature of the solvent and solute

c.rate of stirring

d.polarity of the solvent



3) Red blood cells are placed into pure water. Which of the following statements is true?

a.Water molecules flow out of the red blood cells, causing them to collapse.

b.Water flows into the red blood cells, causing them to swell and burst.

c.The osmotic pressure inside the cells equals the osmotic pressure outside.

d.The osmotic pressure of the cell contents increases, causing the cells to burst.

For this question, I was thinking of a hypotonic solution, but I am unclear of choice d with the osmotic pressure. Is b correct?


Thank you.

 

[durt]

Looks right. I think its the physical pressure inside the cell that causes it to burst. Also, its osmotic pressure would decrease as it became more full of water.

 

[Blueshift5]

Hello,

I would like to provide some feedback and clarification on the content you have provided.

1) The statement about rubbing alcohol is correct. Both water and isopropyl alcohol are solvents in this solution. Solvents are substances that can dissolve other substances (solutes). In this case, water and isopropyl alcohol are both capable of dissolving each other, making them both solvents in this solution.

2) The correct answer for this question is d. The polarity of the solvent can affect the solubility of a solute, while the polarity of the solute, temperature, and rate of stirring can all affect the rate of dissolution (how quickly the solute dissolves). However, the solubility of a solute in a given solvent is mainly determined by the solute-solvent interactions, which are primarily dependent on the polarity of the solvent.

3) The correct answer for this question is c. When red blood cells are placed in pure water, water will flow into the cells due to osmosis. This will cause the cells to swell and potentially burst if the pressure becomes too great. However, the osmotic pressure inside the cells will eventually equal the osmotic pressure outside, leading to a state of equilibrium where there is no net flow of water. This is known as a hypotonic solution, where the concentration of solutes outside the cell is lower than inside the cell, causing water to flow in. Choice d is incorrect because the osmotic pressure of the cell contents does not increase in this scenario. It is the pressure outside the cells that could cause them to burst, not the pressure inside.

I hope this helps clarify any confusion and provides a better understanding of these concepts. Keep exploring and learning!