University:
Eastern Kentucky University
Course:
PHY 131 | College Physics I
Academic year:

2019
Views:

279

Pages:

2
Author:

Alma Hester

Conservation of Mass Activity Worksheet Instructions: Observe and analyze the interactions between the substances pictured in the slide show. Compare the properties of substances before and after each interaction. You will submit your completed worksheet for grading. Data Table On the table below, record your observations before and after the interactions and explain how mass was conserved. Describe the changes in properties that prove a chemical reaction occurred. The first row is an example. Example: Sugar + Heat Steel Wool + Oxygen (Fire) Egg + Heat Water + Heat Observations Before Interaction Observations After Interaction How was mass conserved? Proof of a Chemical Reaction The sugar is in tiny white particles in a pile. Heat is not seen but is implied by the heat source. The pile of sugar in the pot has a mass of 100 grams. The steel wool has a silky appearance and it is rolled up and has a mass of 6 grams. The oxygen is not seen but it is inside of an oxygen tank which has a mass of 1 gram. The egg is place on a flat surface and it has it shell on. The egg has a mass of 45 grams. The heat is not seen but is implied by the heat source of the kitchen. The water is on a glass cup and it has a mass of 75 grams. The heat is implied in a flame of the kitchen. There is a solid, light brown mass at the bottom of the pot. It has a mass of 100 grams. The mass of the sugar is the same in melted form as it is in solid crystal form. There is a brown – mustard color sand in a pile and has a mass of 7 grams. The mass of the steel wool was combined with the mass of the oxygen tank and that was an equal of 7 grams. There was not a chemical reaction. Sugar did not change composition. It only melted. Melting point is a physical property, and this is a physical change. There was a chemical reaction. The steel wool combined with the oxygen of the tank create a new substance called iron oxide. The egg is cooked and it is separate from the shell. It has a mass of 45 grams (the cooked egg 40 grams and the shell 5 grams). The mass of the egg stills the same even if the egg is cooked. The mass of the shell maintains the same too. There was no a chemical reaction. The egg didn’t change composition. It only was cooked and the egg is out of the shell. The water evaporates and it became gas that is coming out of the teapot. The new substance now have a mass The mass of the water remains even if it is gas because it just changed it matter state. There was a chemical reaction. The water changed its matter state and it formed a new substance. of 75 grams in gas released. Zinc + Hydrogen Chloride Sodium Hydroxide + Copper Sulfate The zinc is in a solid state and it has a dirty appearance. It also has a mass of 10 grams. The hydrogen chloride is in a liquid state and it is in a cup. It has a mass of 5 grams.