Mixtures and Solutions
We started this unit by making three separate mixtures - gravel and water; salt and water; powder and water. Then we investigated to see if these mixtures could be separated, either by using a screen or a filter. We found that the gravel mixture could be separated by a screen; the powder mixture was separated by using a filter; but the salt mixture was not able to be separated by either of those! We defined a mixture as a combination of two or more "things" and those "things" retain their own properties.
We discovered that there is a special type of mixture, called a solution, that happens when one thing dissolves in the other (like salt and water). Then we figured out that the only way to separate that salt water solution was to evaporate the water. So we set some dishes of salt water in the window for a couple of days to let the water evaporate. As suspected, the water evaporated and left us with salt crystals. We observed those crystals to discover the properties of them: they are square in shape with an X that goes from corner to corner. Then, just because we were curious, we added water again to see if the crystals would dissolve a second time (they did) and then put the dishes back in the window to see if we would get salt crystals again. We did! Except we found that the salt crystals this time were a little different than they were the first time.
We created a mixture that contained gravel, salt, powder, and water. Then we worked to separate those in a specific order - first we separated the gravel out using a screen. Then we used a filter to separate the powder from the salt. Finally, we used evaporation to separate the salt from the water.
What is a saturated solution? We added spoons of salt to 50 milliliters of water, one at a time. Each time we added a spoon of salt, we shook the container to make the salt dissolve. When no more salt would dissolve, and there was salt on the bottom of the container, we knew our solution was saturated. So a saturated solution is one where no more solid will dissolve.
Our final assessment for science will be split into two parts. These, we will take on June 4th and June 5th, 2014. See below for the study guide that we are in the process of completing together.
We discovered that there is a special type of mixture, called a solution, that happens when one thing dissolves in the other (like salt and water). Then we figured out that the only way to separate that salt water solution was to evaporate the water. So we set some dishes of salt water in the window for a couple of days to let the water evaporate. As suspected, the water evaporated and left us with salt crystals. We observed those crystals to discover the properties of them: they are square in shape with an X that goes from corner to corner. Then, just because we were curious, we added water again to see if the crystals would dissolve a second time (they did) and then put the dishes back in the window to see if we would get salt crystals again. We did! Except we found that the salt crystals this time were a little different than they were the first time.
We created a mixture that contained gravel, salt, powder, and water. Then we worked to separate those in a specific order - first we separated the gravel out using a screen. Then we used a filter to separate the powder from the salt. Finally, we used evaporation to separate the salt from the water.
What is a saturated solution? We added spoons of salt to 50 milliliters of water, one at a time. Each time we added a spoon of salt, we shook the container to make the salt dissolve. When no more salt would dissolve, and there was salt on the bottom of the container, we knew our solution was saturated. So a saturated solution is one where no more solid will dissolve.
Our final assessment for science will be split into two parts. These, we will take on June 4th and June 5th, 2014. See below for the study guide that we are in the process of completing together.
chemistry_unit_study_guide_answer.docx | |
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