Introduction: In this lab, girlfriend willobserve the diffusion the a substance throughout a semipermeable membrane. Iodineis a known indicator because that starch. An indicator is a substance the changescolor in the existence of the substance it indicates. Watch together your teacherdemonstrates just how iodine transforms in the existence of starch.

Prelab Observations: define whathappened when iodine came into contact with starch.


to fill a plasticbaggie with a teaspoon of cornstarch and also a half a cup that water tie bag.(This may already have to be done because that you) to fill a beakerhalfway through water and add ten autumn of iodine. place the baggiein the cup so the the cornstarch mixture is submerged in the iodine watermixture. Wait fifteen minutesand record your observations in the data table While girlfriend arewaiting, price the questions.


You are watching: Why is iodine called an indicator?

1. Specify diffusion. ______________________________________________

2. Define osmosis. ____________________________________

3. Why is iodine referred to as an indicator? _____________________________________________

4. Molecules have tendency to move fromareas that _______ concentration to locations of ______ concentration.

What"s in the Bag?

We"re going come think around concentrationsnow, which substances are much more or less concentrated depends on i beg your pardon one hasthe most stuff in it.

1. I m sorry is moreconcentrated in starch? < manufacturer / baggie >

2. Which is moreconcentrated in iodine? < maker / baggie >

3. V regard come iodine, i m sorry is hypertonic? < manufacturer / baggie >

4. Through regard come starch, i m sorry is hypertonic? < manufacturer / baggie >

Make part Predictions

1. If the bag is permeableto starch, which means would the strength move? < into bag / out of bag >

2. If the bag is permeableto iodine, which way would the iodine move? < into bag / out of bag >

3. If the bag is permeableto iodine, what color would you mean it come change? < orange / violet / no readjust >

What around the solution in the beaker?< orange / violet / no readjust >

4. If the bag is permeableto starch, what color would you mean it to change?< orange / violet / no adjust >

What around the solution in the beaker? < orange / purple / no readjust >


create your monitorings in the table below:

Colorafter 15 minutes
Solutionin maker

See more: What Is The Little Number Below The Big Number S ¹ ³ ⁺ ₄ ₇, Subscript And Superscript

1. Based on your observations,which substance moved, the iodine or the starch?

2. Just how did you recognize this?

3. The plastic baggie was permeableto i beg your pardon substance?

4. Define how the bag is a model for the cell.

5. Map out the cup and also baggie inthe space below. Use arrows to illustrate exactly how diffusion arisen in this lab.

6. What would take place if girlfriend didan experiment in i m sorry the iodine equipment was put in the baggie, and also thestarch solution was in the beaker? Be in-depth in your description.

7. Why is it no a great idea tostore iodine in a plastic bag? related Documents:


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