The purpose of my project is to demonstrate how water temperature affects the dissolving of sugar in liquid. Everything in our universe is made up of particles which are in constant motion. In a solid state particles move the slowest while in a liquid state particles move the fastest. Under the right conditions, solid particles (the solute) when mixed in liquid (the solvent) can form a solution. This occurrence is called dissolving. I wanted to answer the question; does the temperature of water affect the speed at which sugar dissolves? According to my research, there are many different factors the affect the dissolving rate of a substance. The rate of dissolving refers to how quickly a solute dissolves in a solvent. This means how fast or how slow the sugar particles dissolves in the water. Stirring a solution is just one of the things I did to make the sugar dissolve faster.
Other factors that make a difference include the size of the particles such as sugar cubes or crystals, the temperature of the water, and the concentration of the solution. Learning that these factors contribute to the rate of dissolving a solute, I hypothesize that the increase in water temperature will decrease the dissolving time of the sugar cube and sugar crystal.For this experiment the temperature of the water represents the independent variable. The dependent variable is represented by the dissolving time of the sugar cube and sugar crystal. The amounts of water, sugar cube and crystal, brand of sugar and the sugar measurements represent the constants. The cold water is the control.
White sugar cubes
Brown sugar crystal
Spoon for stirring
Note pad for findings
3. Step-By-Step Procedure:
First, I measured a ½ cup of hot water using a measuring cup and poured measurement into one (1) glass. I added five (5) sugar cubes and started the stopwatch then began stirring with a spoon. I stirred until the sugar dissolved, making sure to note the time it took for the sugar to dissolve. I wrote the results in my notepad. The process was repeated in the next glass of hot water with (1) tablespoon of brown sugar crystal to the other glass of hot water. Next, I measured another ½ cup of ice water and poured it into one (1) glass. Once again I added five (5) sugar crystals and started the stopwatch then began stirring with a spoon. Again I stirred until the sugar dissolved, recorded my finding and repeated the process with one tablespoon of brown sugar crystal this time. Finally, I followed the steps of putting five (5) sugar crystals and one (1) tablespoon of brown sugar crystals into separate glasses of prepared ½ cup of lukewarm water. I stirred and noted the amount of time it took for the sugar to dissolve.
Dissolving Rate of Sugar
Hot (146° F)
Room Temperature ( 88° F)
Cold (35° F)
White Sugar Cube
Brown Sugar Crystal
The warmer the water the faster the particles moved around. This means that the water and sugar particles will mix together faster, so the boiling water should have dissolved the sugar fastest. The cold water should have dissolved the sugar the slowest because the particles will be moving around much more slowly.
Temperature as discussed is one of the factors that affect the rate of dissolving. The hot water measured 146 degrees Fahrenheit and was consistent with the hypothesis that the sugar will dissolve faster. Temperature affected the rate at which the white sugar cube dissolved slower than the brown sugar crystal and took about 37 seconds to dissolve. The brown sugar crystal was the winner with 16 seconds. This shows that the solvent molecules move more rapidly at higher temperatures and strike the glass surface more often and harder, causing he rate of dissolving to increase. Secondly, the size of the sugar crystals and sugar cube w also affected how quickly the sugar dissolved in the hot water. Research indicates that the rate at which a solid dissolves is governed by the size of the solute particles.
A solid can dissolve only at the surface, so small crystals dissolves faster than larger ones, hence the brown sugar crystals dissolved faster than the white sugar cubes. Another factor that affected the dissolving time was stirring of the sugar particles in the hot water. The stirring motion helped to distribute the sugar particles rapidly through the solution and more hot water was brought into contact with the sugar, causing the sugar to dissolve much faster.The dissolving time of sugar cube and sugar crystal in the room temperature water did not surprise me. The solute will generally dissolve faster if the water in which it dissolves is hot or warm. In this trial, the brown sugar crystal dissolved at a faster rate at 58 seconds while the white sugar cube came in second with one minute and nineteen seconds (1:19).
It is evident as shown by the bar graph; cold water lost the match. Although the sugar dissolved at a much slower rate, it is definitely not the best temperature to dissolve solutes like sugar. It did dissolve entirely as a result of vigorous stirring action with water temperature measuring 35 degree Fahrenheit, but at a rate of two minutes and thirty one seconds for white sugar crystals and one minute and five seconds for the brown sugar crystals.
Looking back on the results obtained from the data table, and how the different water temperature affected the rate at which the sugar dissolved, it is possible to draw several conclusions. As stated in my hypothesis, the increase in the temperature of water will affect the rate of dissolving by speeding up the process. The experimental procedure and observation showed that the sugar are able to move faster in higher water temperatures which results in the fast process of dissolving. This data supports the hypothesis and indicated that sugar will dissolve quickly at higher water temperatures. It also showed that sugar dissolved faster when stirred and also because the brown sugar crystal was smaller in size when compared to the white sugar cube.Given a second chance, I would most likely experiment with white sugar crystal and brown sugar crystal. I believe that a closer time is possible since they are both closer in size.
How temperatures affect the dissolving rate?
Solubility and factors that affect solubility
Factors that affect rate of dissolving solubility