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Salt in Boiling Water. By John-Paul Evans. Purpose. What does ice do to hot boiling salt water and why does it do it?. Hypothesis . Ice in measuring cups causes salt water to cool slower than ice in measuring cups without salt. . Interesting Facts.
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Salt in Boiling Water By John-Paul Evans
Purpose • What does ice do to hot boiling salt water and why does it do it?
Hypothesis • Ice in measuring cups causes salt water to cool slower than ice in measuring cups without salt.
Interesting Facts • First, heat does not flow from hot to cold. • Second, salt water freezes 30 to 40 degrees • Third, hot water freezes faster than cold water. • Fourth, boiling water and adding salt takes longer to boil. • Fifth, adding salt to water raises its boiling point.
Materials • Pot of water • Hot Plate • Salt • Several Ice Cubes • Watch with Minute Hand • Pencil and Paper • Two Thermometers • Two Glass Measuring Cups • Tablespoon • Graph Paper
Procedure • Set pot of water on hot plate and turn on hot plate until water boils. Ask mom or dad to help with this step. • Put two ice cubes in each measuring cup. • Put a thermometer in each cup. • Put two tablespoons of salt in one measuring cup. • Once water comes to a steady boil pure one half a cup of water in each cup. • Observe what happens to the boiling water. • Take temperature reading from the thermometer every ten seconds. Have mom or dad help time the ten second intervals. • Record temperature change each ten seconds in each cup. • Plot a table of temperatures of each cup using one axes and time of the other.
The data seems to show water with salt cools more slowly than water without salt.
Analysis • Boiling water stopped and start cooling immediately. • Temperatures and times show water cooling at different rates in each cup. • Salt water cooled slower in ice than water without salt in ice. • Did the experiment test your hypothesis? Yes • How do you know? Because the data tells me so.
Conclusion • Was your hypothesis correct? Yes • What would you change in the experiment and why? I would add more salt to see if I could slow cooling. • What are some new questions you have?
New Questions to Research • Can more salt slow water cooling? • Can more ice change the cooling of salt water?