If the substance no longer had an aqueous solution after the double replacement, then the substance would be a precipitate. Setup and Materials: The Reaction: Student Work: The student above recognizes that this is a chemical reaction. This unit focuses on chemical properties and chemical reactions. When I meet with this group, I have them discuss what is occurring to the energy and molecules as water freezes or evaporates and then they can come to the correct conclusion. Do not shake it too hard, as it may result in a leakage of the mixed solution that could cause an error in the result.
Discussion i Analysis of Result Whether or not a reaction will form a precipitate is dictated by the solubility rules. In the scheme of teaching chemistry, this activity should be done after students have written formulas and balanced equations and while the class is learning types of chemical reactions and evidences for chemical reactions. Student Work: In the first question, this student demonstrates some of the challenges that many students have in this lab. Based on your results, you will write complete and net ionic equations for each reaction that has taken place. The chemist describes this process first as a complete ionic equation.
This lab addresses only the double replacement reaction also known as double displacement. Then, in an upcoming lesson, I can conference with these groups. After reading the skill have the students rank their current level of mastery on a scale of 1 to 4 4 being mastery. Repeat procedures 1-4 for all chemical pairs listed on your data table. Students often have a difficult time understanding this energy transfer.
I believe that this experiment was one that would clearly prove this to be true. Students who need longer to complete assignments can choose to write the names of the ionic compounds or balance the equations instead of doing both. Students will perform a set of double replacement reactions. Water is a liquid and has a boiling point of 100 degrees Celcius. What are some visible evidences of a chemical reaction? For our case, it was a bit of a pity that we did not have enough test tubes for mixing the solutions.
There was gas production when the bubbles formed. If applicable ie: if you classified it as a precipitation reaction include the net ionic equation as well. This question can actually cause students to second guess themselves. Solution became cloudy white: Precipitate formed. Then the teacher will give additional examples from the double replacement example document below.
This makes the color initially change to a white precipitate and then over a few seconds to a murky brown color with release of I2. Precipitation reactions usually involve ionic compounds, and although all ionic compounds are strong electrolytes they are not equally soluble. The water simply turned green because the food coloring was green. The lid should pop up into the air several feet. We are just like you, bunch of people which are highly treasure original work from every one, without exception! We also thought that among the ones forming a solid, not all would have the same color.
The well plates sometimes feel hot. In Question 2, some students show that they are still having the misconception that phase changes and dissolving are physical changes and that when a new color appears, that would indicate a chemical change. Rubric: There are six reactions. The teacher will show students how the positive ion cation of one reactant combines with the negative ion anion of the other reactant. The number atoms of reactants and products in a chemical reaction must equal because of the law of conservation of mass. We decided to investigate more detailed and specific facts through the process below. Students utilize reading, writing, and speaking strategies in order to develop scientific literacy.
In the worst situation, this could even cause a difference in the result. The second question however, this student has some misconceptions. If not required to include physical properties, students will focus on physical properties because that is what they are most comfortable with. This is simply not effective for their learning. The teacher copy of the lab instructions includes answers to the post lab questions and a student data table with the answers filled in. It is printed on one page and folded into a four page document.