First, you have to find the molar mass of an element. Explain the differences you may have observed. Some anhydrous salts can absorb moisture from the air to become hydrated.
The Lab The next thing we did, was the amazing bubble gum lab. If a spill of either chemical occurs, rinse under running water and report the accident to your instructor. The crucible was then set in place a few inches up from the top of the Bunsen burner.
Determine the number of moles of the anhydrous Salt: Heat the crucible and its contents, gently at first and then strongly, for approximately minutes. Students will understand the concept of percent composition of compounds and be able to perform the associated calculations.
Qualitative observations of crystal after first and second heating: You can provide crucibles and Bunsen burners or a drying oven and any other equipment that you would routinely use in the conventional Percent Composition of a Hydrate Lab most of us are familiar with. Also, when taking the lid off the crucible to put the Copper Sulfate in it, water may have entered the crucible, and added mass that was not there when it was weighed the first time, before the Copper Sulfate was added.
Percent Composition of Compounds Standards Addressed: Give students 2 practice compounds that include subscripts and polyatomic ions Lab Activity: The hydrate will probably have a different appearance when the water has been driven off.
The number of moles of water per mole of ionic substance is usually an integer. Add approximately 1 gram of potassium chlorate to the crucible.
I then gave them sample lab data for other hydrates, so that they could find how many moles of water were attached to each of the hydrates referred to.
The sugar will dissolve when you chew it, leaving behind only the gum. Note that heating the sample too intensely at this point could cause loss of the sample via splattering, and could crack the crucible. What are the "cons" to doing this lab.
Name the hydrated crystal used in this lab. Get the mass of a paper cup. Then pour the resulting solution into tube 3. Allow the crucible and contents now an anhydrous solid we hope to cool. There were many factors that may have affected the results of the experiment.
One way is that it produced a brown-colored carbon build up on the crucible, altering the mass data higher than it should have been. Since there was a small amount of blue left within it, not all of the water had been evaporated.
Total gum — chewed gum Calculate the percent sugar in the gum. Procedure First a lid was chosen so the water could not get back into the crucible.
Polish the magnesium ribbon with the steel wool and fold the ribbon to fit into the bottom of the crucible. Heat with a bunsen burner for 2 minutes, gently at first and then strongly.
For the extremely busy teacher, it doesn't get much better than this for a great chemistry lab. The potassium chlorate sample will be heated in a specialized "container".
Students MUST wear safety goggles. Easy set-up and easy clean-up. Separate the sources of error into Avoidable errors and Suggest modifications to the experiment, so that your results may be more accurate. Most hydrates lose their water of hydration at temperatures slightly above oC.
If the sample from step 7 is not within 0.
This lab illustrates (1) the law of conservation of mass and (2) the law of constant composition. 1. The total mass of the products of a reaction must equal the total mass of the reactants.
2. In terms of the mass of each element present to the total mass of the compound (mass percent). Law of Constant Composition Lab: Magnesium and Oxygen Words Nov 19th, 6 Pages Purpose: To determine the percent magnesium by mass in magnesium oxide and to observe if the percentage composition is constant by comparing class results.
This resource is a lab in which students test percent composition. From the introduction: "In this lab you will be given a mixture of either sodium or potassium chlorate and an inert material like sodium chloride.
Lab: Law of definite proportions. Percent composition of Magnesium oxide. In this lab you will test and validate the law of definite proportions.
To do this you will determine the composition by mass of magnesium oxide, calculate the percent composition and compare your results with other groups working on the same experiment. “During the lab students will be determining the percent composition of sugar in gum followed by a post lab assignment doing more complex calculations.
PRE-LAB Hydrates “water of anhydrou The Δ sig accurately due to the In this exp (II) sulfate This inves 2. Find the percent of water lost from the original hydrate (remember that percentage is “the part divided Composition of lanos-clan.comPercent composition lab