Quiz: Physical Processes Flashcards
Define and give an example of osmosis
A process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated solution, thus equalizing the concentrations on each side of the membrane.
Example: salt water
Define and give an example of diffusion
The spreading of something more widely.
Example: perfume
Define and give an example of semipermeable membrane
A semipermeable membrane is a type of biological membrane that will allow certain molecules or ions to pass through it by diffusion.
Example: osmosis
Define and give an example of homeostasis
The tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
Example: human’s body heat
A solution is composed of what two parts?
It is composed of both a solute, the substance that dissolves, and a solvent, which is the majority of the solution.
What is the name given to the solid part of a solution?
Solute
What is the name given to the liquid part of a solution?
Solvent
Describe Brownian movement and its cause:
Brownian movement is due to random vibrations of water molecules and is only a vibrating motion. It is a zigzag or irregular motion exhibited by minute particles of matter when suspended in a fluid.
How does heat affect Brownian movement?
Molecules move faster as the temperature increases.
Does an increase in temperature increase the rate of a chemical reaction? Why?
Particles can only react when they collide. If you heat a substance, the particles move faster and so collide more frequently. That will speed up the rate of the reaction.
If you had a 10% salt solution on one side of a beaker and a 5% solution on the other side and they were separated by a semipermeable membrane, which way would the water move? Why?
They would move to the side that has a 10% salt solution. It moves to that side so both sides could remain balanced in concentration.
Describe the artificial cell experiment and explain the results.
The substances inside the cell were salt, starch, and water. There was also water on the outside of the cell. At the end, the water ended up moving into the cell and salt ended up going into the distilled water. It showed that water moves from a high concentrate to a low one and salt is small enough to fit through the pores and bond with water.
How do you test for the presence of salt? Starch?
We test for the presence of salt by using silver nitrate.
We test for the presence of starch by using iodine.
Give the chemical symbols for potassium permanganate, table salt, and silver nitrate:
Potassium permanganate: KMnO4
Table salt: NaCl
Silver nitrate: AgNO3
Did water move in or out of the cell? How was this determined?
Yes. Before adding the solution into the cup of distilled water, we had to weigh it on a scale. After adding the solution into the cup of distilled water, we had to wait thirty minutes and weigh it again to see if it weighed more or weighed less.
