What makes ice melt faster salt or sugar hypothesis?

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Key concepts Water Ice Chemistry Solutions Phases of matter  

Introduction

Do you sometimes dump ice cubes into a drink to help keep cool on a hot summer day? Have you ever watched the ice cubes melt and wondered how you could make them melt more slowly—or even faster? In this science activity you will get to try some different, common household substances to try and answer this question: What will help a solid ice cube turn into a liquid puddle the fastest?  

Background

Temperature isn't the only thing that affects how a liquid freezes—and melts. If you've ever made homemade ice cream the old-fashioned way using a hand-crank machine, you probably know that you need ice and salt to freeze the cream mixture. Similarly, if you live in a cold climate, you've probably seen the trucks that salt and sand the streets after a snowfall to prevent ice from building up on the roads. In both of these instances salt is lowering the freezing point of water, which means that the water needs to be colder to turn from liquid into ice. For the ice cream maker, the temperature of the ice–salt mixture can get much lower than if just using normal ice, and this makes it possible to freeze the ice cream mixture. For the salt spread on streets, lowering the freezing point means that ice can melt even when the outdoor temperature is below water’s freezing point. Both of these events demonstrate “freezing point depression.”   Salt mixed with water is an example of a chemical solution. In a solution there is a solute (salt in this example) that gets dissolved in a solvent (water in this case). When other substances are mixed with water they may also lower its freezing point. In this science activity you'll investigate how salt, sand and sugar affect water's freezing point.  

Materials

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Oreos Posts: 1 Joined: Wed Jan 06, 2016 4:50 pm Occupation: Student

Post by Oreos » Wed Jan 06, 2016 4:56 pm

Is this a good hypothesis? If I add salt, sugar and sand to different samples of ice, the sample that has the salt added to it will melt faster than the other samples, because salt melts ice faster than sugar or sand.

roygoli Former Expert Posts: 40 Joined: Mon Aug 24, 2015 2:30 pm Occupation: Student: 11th grade Project Question: I'm volunteering as an expert for this program. Project Due Date: N/A Project Status: Not applicable

Post by roygoli » Thu Jan 07, 2016 3:44 am

Hi Oreos! The beginning of your hypothesis sounds great. However, the ending could use a little work. "because salt melts ice faster than sugar or sand." Here you're kind of making the experiment pointless by actually claiming that you already know that salt melts ice faster than sugar or sand. Isn't that what you're testing? If you're going to add a "because" to your hypothesis you need to first establish that you don't know if salt actually does or doesn't melt ice the fastest yet. Now without that information, determine why you think that salt would melt ice the fastest. Is it due to its structure, bond type etc... Here's an example hypothesis from a different experiment. It might help clarify the point of the "because" statement:

If the temperature of sea water increases, then the amount of salt that will dissolve in that water

increases because with increasing temperatures, particles gain more energy and thus move faster, leading to more contact between them.

See how the hypothesis is a logical guess, prediction (not a fact yet!), based off of the information you already know?
Now you try Good luck!

krazykidrg Posts: 3 Joined: Thu Jan 14, 2016 5:00 pm Occupation: Student

Post by krazykidrg » Thu Jan 14, 2016 5:06 pm

Can you tell us about ice and crap. We wanted to know what makes ice melt fastest. We are melting ice with salt sand and sugar. Can you tell us some information about it. It would be a big help if you could respond. We wont have to feel the wrath of our teacher if you do so. Thank You

tdaly Former Expert Posts: 1415 Joined: Sat Nov 08, 2003 11:27 pm Occupation: Planetary Scientist Project Question: N/A Project Due Date: N/A Project Status: Not applicable

Post by tdaly » Fri Jan 15, 2016 10:42 am

Hi krazykidrg,

What, specifically, are you having trouble with? The background section of the project idea and sites linked to therein have a lot of information about how these materials help melt ice. Posting questions on the Ask an Expert Forums is most helpful once you have specific questions that you need help answering.

All the best,
Terik

krazykidrg Posts: 3 Joined: Thu Jan 14, 2016 5:00 pm Occupation: Student

Post by krazykidrg » Fri Jan 15, 2016 10:33 pm

Well, i need to know how salt melts ice. I also need to know how sugar and sand melts ice. All of this will be in water too. Ill make a list of questions. 1. How does salt melt ice in water? 2. How does sugar melt ice in water? 3. How does sand melt sugar?

4. Does the ice being in water effect how the salt, sand, and sugar melt it?

tdaly Former Expert Posts: 1415 Joined: Sat Nov 08, 2003 11:27 pm Occupation: Planetary Scientist Project Question: N/A Project Due Date: N/A Project Status: Not applicable

Post by tdaly » Mon Jan 18, 2016 11:44 am

Hi krazykidrg, Salt and sugar melt ice because they lower the freezing point of water. Instead of freezing at 32 degrees F (0 degrees C), a mixture of salt and ice (or sugar and ice) will freeze at a lower temperature. You can read more about that - and find the answers to the other questions you have listed - at this website:

//chemistry.about.com/od/howthings ... lt-ice.htm

All the best,
Terik

krazykidrg Posts: 3 Joined: Thu Jan 14, 2016 5:00 pm Occupation: Student

Post by krazykidrg » Wed Jan 20, 2016 6:55 pm

Thank u. U were a BIG help. Now we dont have to feel the wrath of our teacher.

tdaly Former Expert Posts: 1415 Joined: Sat Nov 08, 2003 11:27 pm Occupation: Planetary Scientist Project Question: N/A Project Due Date: N/A Project Status: Not applicable

Post by tdaly » Thu Jan 21, 2016 8:59 am

Hi krazykidg,

Glad to help! Feel free to post back if you run into additional questions when run the experiments.

All the best,
Terik