Key Concepts

For a fluid to dissolve a solid, the molecules of the liquid and solid must entice one another.The bond between the oxygen and also hydrogen atom (O–H bond) in sugar (sucrose) gives the oxygen a slight negative charge and the hydrogen a slight hopeful charge. Sucrose is a polar molecule.The polar water molecules entice the an adverse and positive areas on the polar sucrose molecules which renders sucrose dissolve in water. A nonpolar substance favor mineral oil does not dissolve a polar substance choose sucrose.

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Summary

Students will certainly observe the dissolving of the sugar coating indigenous an M&M as soon as it is placed in water. Students will certainly then help design one experiment to view if the form of fluid the M&M is inserted in affects exactly how much that the coating dissolves.

Objective

Students will be able to explain, top top the molecule level, how the polar characteristics of water and also sugar communicate so the water dissolves sugar. Students will be able to identify and control the variables in your experiment. College student will likewise be able to describe why a nonpolar liquid, such together mineral oil, is not an excellent at dissolving sugar.

Evaluation

Download the student activity sheet, and also distribute one every student as soon as specified in the activity. The activity sheet will serve as the “Evaluate” component of each 5-E great plan.

Safety

Be certain you and the college student wear correctly fitting goggles. Isopropil alcohol is flammable. Keep it away from flames or spark sources. Read and follow all warnings top top the label. Dispose of isopropil alcohol and also mineral oil follow to regional regulations. Warning studens no to eat the M&M’s.

Materials for Each Group

M&M’sWaterMineral oilIsopropyl alcohol (70%)Small white plastic plate3 clear plastic cupsWhite paper

Have students ar an M&M in a cup that water and observe.

Question to Investigate

What happens to the sugar and also color coating of an M&M when it is put in water?

Materials

Clear plastic cupWaterM&MWhite paper

Procedure

Pour enough room-temperature water right into clear plastic cup so that the water is deep enough to fully cover one M&M and place this cup on a piece of white paper.

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Once the water has actually settled, location 1 M&M in the facility of the cup. Be mindful to store the water and also M&M as still together possible. Observe for about 1 minute.

Expected Results

The coating will certainly dissolve native the M&M, revealing a white great under the color and then the brown coco underneath. The fancy coating that the M&Ms will certainly collect in a circular pattern approximately the M&M. Student may also mention the white streaks in the water native the street coating.

Discuss student observations.

Ask students:

What perform you notification about the M&M and the water? The shade comes off and also moves with the water in a one pattern. What carry out you think is happening once the color and sugar come off the M&M? allude out to students that because the water makes the fancy coating come off the M&M and also mix into the water, the water is dissolve the sugar and color.

Note: There room actually two procedures happening in this activity. The color and also sugar room dissolving in the water but they are also diffusing. In bespeak to emphasis on the amount that dissolves from an M&M, students have to look in ~ the lot of coating absent from the M&M, instead of the dimension of the one of shade in the water.

Knowing what you do about the polarity that water, why perform you think water dissolves sugar?Students might think the sugar is do of ionic bonds choose salt. Or they can think the sugar has positive and negative areas and this is why water is attracted to it.Explore

Have students command an experiment come compare just how well water, alcohol, and oil dissolve the sugar and also color coating of an M&M.

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Ask student to do a prediction:

Do you think water, alcohol, or oil would certainly be much better at dissolving the sugar and also color coating of an M&M?

Discuss with students just how to style an experiment to compare exactly how well water, alcohol, and vegetable oil dissolve the color and sugar coating from an M&M. Be certain students recognize variables such as:

Amount the water, alcohol, and also oil usedTemperature of each liquidSame shade of M&MTime and also location the M&M’s are inserted in each liquid

Question come Investigate

Is water, alcohol, or oil better at dissolving the color and also sugar coating native an M&M?

Materials

3 M&Ms (same color)WaterMineral oilIsopropyl alcohol (70%)3 clean plastic cupsWhite paper

Procedure

Label 3 cups Water, Alcohol, and Oil. Include 15 mL the water, alcohol, and also mineral oil to their labeled cups.Place the three cups top top a white sheet of paper.

At the exact same time, include 1 M&M to every liquid. Then gently swirl the liquid and also M&M in every cup for around 30 seconds.

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Expected Results

Water—The sugar and also color dissolve from the M&M. Alcohol—The shade dissolves only slightly and also the street coating doesn’t seem to dissolve.Oil—Neither the color nor the sugar dissolves