DATA Qualitative observations of crystal before heating: Assign Homework — calculate the percent composition of 3 compounds. Students MUST wear safety goggles. Record the mass after the final heating as the constant mass of sample, crucible, and lid in your data table. Each person chews their piece of gum for 5 minutes.
Use 4 decimal places for the mass. First, you have to find the molar mass of an element. Using an oven to heat the crucible and substance within slowly, evenly, and at a controlled temperature could have easily prevented these inconsistencies.
Place the crucible on the triangle with the lid slightly tilted. Visit often and post your comments freely. Place the crucible and cover on the triangle with the lid slightly tipped. But in all seriousness, the bubble gum lab. The mass of the crucible and its contents was written down, and was carried back to the lab area to cool off.
Using your answers from 3 and 4, determine the empirical formula of the copper sulfate hydrate. When an ionic solid is crystallized from water solution, the crystal which forms often contains chemically-bound water molecules.
Followed by an overall statement of the success of the lab. From the mass of carbon dioxide released, students can mathematically determine the amount of carbon in the released sample, and therefore the percent composition of carbon in sodium hydrogen carbonate.
When the crucible was in transportation from the lab area to the scale, and while waiting in line for the scale, the crucible may have cooled and allowed water to reenter the Copper Sulfate and the crucible itself. This can be proved by the color of the Copper Sulfate Pentahydrate, which after heating, did not turn to a fully white color.
Free essays on Chemistry posted on this site were donated by anonymous users and are provided for informational use only. To find the percentage of water in it, the Copper Sulfate was heated inside a crucible. Heat the crucible very gently to avoid spattering of the crystal.
Discuss how errors could have occurred try to avoid simple explanations such as "perhaps we measured the mass of the magnesium sulfate wrong Allow the crucible to cool on the triangle for 2 minutes.
With the final mass measurement, the amount of water that evaporated was found, and with that, the percentage of water in Copper Sulfate Pentahydrate was found. Write the formula for barium chloride dihydrate. After the desired flame was set, the crucible was then heated for 10 minutes, drying off the inside of the crucible.
Possible Connections To Other Subjects: Discuss how close your experimental value is to your actual value. Could you leave the cover off each time you measure the mass of the crucible and its contents and still get accurate results. Each student gets a piece of gum.
Values recorded in lab: Thus we can calculate the percent of sugar in the gum. Allow the crucible and contents now an anhydrous solid we hope to cool. Crush the white ash in the crucible with the end of a stirring rod.
By comparing these masses, the percentage of water was found. Find the new mass of the crucible, lid and anhydrous crystal. The sugar will dissolve when you chew it, leaving behind only the gum. Allow the crucible to cool for 5 minutes.
Record any qualitative observations.
Why do you need to use a cover for the crucible. So we started off class today by reviewing Avogadro's number 6. Place the lid on the crucible so that it is slightly ajar. Penny Lab & Rubric. Pennies are often mistakenly thought to be made of solid copper.
Pennies sincehowever, are made up mostly of zinc. Your job is to work with your group to determine the percent composition of a post penny.
In this lab, students will calculate the percent composition of sugar in gum and the percent composition of water in popcorn kernels. Resource Type. Learn the difference between the empirical formula and chemical formula. Learn how to calculate the percent composition of an element in a compound.
Popcorn Lab & Rubric. The general form for this lab is: Question, Hypothesis, Materials, Procedures, Data, Conclusion. This is a mini-lab: All standard sections are present but unlike most of our labs, not a great deal of elaboration is required.
"What is the percent composition of water in the kernals of a bag of pop corn?" (1 pt. Introduction. Chemists can describe the composition of a chemical compound in at least three different ways.
The first way is to define the. percent composition.
of a compound; this is the percent of each element found in the compound by mass. For example, a chemical compound called acetylene is composed of % carbon stays at the lab. Percent Composition of Hydrates Essay Sample.
Purpose: Demonstrate proficiency in using the balance and Bunsen burner. Determine that all the water has been driven from a hydrate by heating your sample to a constant mass.Percent composition lab