Sugary Sweet Solutions

Grade 5: Nature of Science and Changes in MatterSarah Rhodes-Ondi, ELC Naturalist

BackgroundMatter can be combined into solutions, compounds and mixtures.

Solutions are a special type of mixture called a homogeneous mixture. They are

made up of two parts: a solute, something that dissolves and a solvent,

something that does the dissolving. Homogeneous mixtures are found around

your house such as brewed coffee, tea, saltwater and sugar water. These are

combinations of matter that thoroughly mix and particles do not appear to sink

out of solution. Heterogeneous mixtures do not completely mix. These are

things like orange juice, sandy water or a glass of water with ice cubes in it.

Heating solutions makes the molecules inside move around faster while cooling

solutions makes the molecules move slower.

In this experiment we are going to explore how temperature influences

how much sugar, a solute, can be dissolved in water, a solvent. If more solute is

added to a solvent than the solvent can absorb, some of the solute will sink out of

the solution. We call this a “saturated” solution meaning the solvent cannot

absorb any more solute.

Steps of the Scientific Method

1. State Problem What question are you trying to answer by doing this experiment? Write “Does the number of tsp of sugar that can be added to water

change with temperature?” in #1 on your Laboratory Form. 2. Do Research

Read about your topic in books. Talk to experts. Observe the real world.

Become the expert! Write anything you learn that will help you plan and explain your

experiment in #2 on the Lab Form. 3. State Hypothesis

Based on your research, make an educated guess about what will happen when you do your experiment using what you learned from your research (#3 Lab Form). This should be written with a prediction and not in question form.

4. Design Experiment Independent Variable : What factor (treatment) are you testing?

Hint: Temperature of water. Dependent Variable : What will you measure or observe? Hint:

number of tsp of sugar can add to water. Can you think of something else you could measure?

Control : What is something you do not change at all? Hint: Room temperature water.

Replication : How many replicates will you do? Scientists run a minimum of 5 in case they make a mistake. Hint: Each group is running 1 replicate of this experiment.

Record all of these in Lab Form #4.

5. List Materials Recorded in Lab Form #5. Each group will have 1 full set. Teaspoon ½ cup table sugar (sucrose) 3 Chopsticks Chinese food soup containers (clear plastic container that can

handle heat). Use glass beakers if using over an open heat source. Hotplate or microwave to warm water. Thermometer

6. Test Hypothesis & Data Collection Procedure: Do experiment!

o Record the list of steps below in Lab Form #6.o Have partner record all tsp added in Lab Form #7. o Place ½ cup of water in container marked control. This

water will stay at room temperature, 25°C.

o Place ½ cup of water in container and place container upright in ice bath. (Note: do not add ice directly to water). Let sit for 20 min or until reach 15°C.

o Heat up ½ cup of water to at least 35°C. Pour hot water in plastic container. (Each group is doing 1 replicate will need entire class to have water at the same temp.) Let cool if needed to desired temp.

o Start with heated or cooled water when temperature is right. Add 1 tsp of sugar at a time and stir after each addition (Note: quickly add sugar and stir because if go too slow temperature in containers will change to room temperature). Have your partner keep record of the number of tsp you are adding in the Data Collection section. Stop when many of the sugar crystals are sitting at the bottom. Check temperature of solution after reached saturation.

o Repeat sugar addition with each container. Stop when each solution reaches saturation. Record temperature at this point.

o Ask friends how many tsp of sugar they needed to add to fill in the data sheet.

7. Analyze Results What temperature of water dissolves the most sugar? The least

sugar? Record in Lab Form #8. Make a bar graph of your results.

8. Draw Conclusions

Record answers in Lab Form #9 Did your data support your hypothesis? Why? What is happening to the molecules in the water that dissolved the

most sugar? What type of mixture did you just create? Which part is the solute

and which is the solvent? What did you learn? How could you change the experiment next time you run it?

Lab Form

1. State Problem

2. Research

3. Hypothesis

4. Design Experiment

5. Materials

6. Test Hypothesis

7. Data Collection (ask each group for their results to fill in d-h).

a. Observations:b. Temperature of water before and after add sugar.

Room Temp Heated Cooled Before_____ Before_____ Before_____After ______ After______ After______

c. Number of tsp Room Temp Heated Cooledd.e.f.g.h.

8. Analysis of Results

9. Draw Conclusions

Referenceshttp://www.sciencekids.co.nz/experiments/dissolvingsugar.htmlhttp://www.instructorweb.com/lesson/compoundmixture.asphttp://www.elmhurst.edu/~chm/vchembook/106Amixture.html

Note to Teachers:

Feel free to vary the temperatures used in this experiment based on your

resources. Less water takes less sugar to saturate the solution. If you are

running short on sugar, decrease the amount of water used in the experiment.

The higher the temperature the water is heated to the more sugar the solution

should be able to absorb. The cold temperature water should absorb the least

sugar out of all three.

If you have time, have the kids calculate the mean of the number of tsp

added for each temperature. This experiment can be done with any type of

solute. For another variation of the experiment, try it with different solvents.

Sunshine State Standards

Use vocabulary: mixtures, solutions, molecules, experiment, variable, control

group.

Concepts: Investigate solutions and mixtures, how are they alike and different.

Skills: Create data charts, differentiate between mixtures and solutions.

BenchmarksScience

SC.5.N.1.1

SC.5.N.1.3  

SC.5.N.1.4  

SC.5.N.2.1  

SC.5.P.8.2

Mathematics MAF.5.G.1.1

MAFS.5.G.1.2

Description

Define a problem, use appropriate reference materials to support scientific understanding, plan and carry out scientific investigations of various types such as: systematic observations, experiments requiring the identification of variables, collecting and organizing data, interpreting data in charts, tables, and graphics, analyze information, make predictions, and defend conclusions. Cognitive Complexity: High  

Recognize and explain the need for repeated experimental trials. Cognitive Complexity: Moderate

Identify a control group and explain its importance in an experiment. Cognitive Complexity: Moderate  

Recognize and explain that science is grounded in empirical observations that are testable; explanation must always be linked with evidence. Cognitive Complexity: Moderate

Investigate and identify materials that will dissolve in water and those that will not and identify the conditions that will speed up or slow down the dissolving process. Cognitive Complexity: High

Use a pair of perpendicular number lines, called axes, to define a coordinate system, with the intersection of the lines (the origin) arranged to coincide with the 0 on each line and a given point in the plane located by using an ordered pair of numbers, called its coordinates. Understand that the first number indicates how far to travel from the origin in the direction of the one axis, and the second number indicates how far to travel in the direction of the second axis, with the convention that the names of the two axes and the two coordinates correspond. Cognitive Complexity: Level 1: Recall.

Represent real world and mathematical problems by graphing points in the first quadrant of the coordinate place, and interpret coordinate values of point in the context of the situation.