The purpose of this week’s Lab is to find the weight of different objects and record my findings/data. I will record my data on a chart. My observations will determine why each scale has a different weight for the same object being weighed. The two techniques practiced here are direct weighing and weighing by difference. The skills required vary depending upon the kind of balance used. In this lab I will practice the techniques required to use a centigrade balance and electronic balance.
In general, efferent substances have the same exact densities even if they occupy the same volume or have the same mass. Throughout this experiment I was weighing the same items on different scales and I was very surprised by the results. Direct weighing simply requires learning how to read the mass directly from the balance. Weighing by difference requires recording the mass of an object in a container, recording the mass of the container only, and then calculating the mass of the object by subtracting the mass of the container from the mass of the object in the notation.
The centigrade balance has two-decimal place points and the electronic balance has three-decimal place points. Each balance displays a different weight for the same objects. Procedure First you will need to weigh a slug on a centigrade balance using the direct-weighing technique. The centigrade balance can be found under the balances option under the equipment menu. Select the centigrade balance and add one slug from the chemicals dialog box. Record the slug mass in the observations. Weigh the same slug directly n another centigrade balance.
Obtain a second centigrade balance from the balances option under the equipment menu and place it under the first centigrade balance so that the pans line up under each other. Select the centigrade balance with the slug and choose pour/decant from the procedures menu. Record the mass of the slug. You will repeat these steps for the next experiments, which are, weighing by difference and weighing the unknown. Observations and Results Part l: Centigrade Balance Direct weighing method: Mass of slug _3. 5 Mass of beaker 49. 6 Mass of beaker + slug 52. 65 Mass of slug 3. 05 Part II: Electronic Balance Mass of slug _3. Egg Weighing by difference: 50. Agog 53. Egg 3. Egg Part Ill: Average Mass of Copper Slug With an Electronic Balance Number Slugs Weighed Mass 2 5. Egg 3 8. Egg 4 1 1. Egg 5 13. Egg Average 8. 61* Part lb. Determining the Mass of Unknown Weights Unknown (#1 -Fee) Mass of beaker + unknown 74. Egg Mass of unknown 24. Egg Unknown (#2-Fee) 75. Egg 25. Egg Discussion
After completing this experiment, I now know that weighing the same object on an electronic balance would weigh slightly more than on a centigrade balance. It is also important to always make sure the centigrade balance is set to zero for an accurate reading. Conclusion I found out that the unknown objects weigh more than the mass of a slug and a beaker combined. To find the mass of the objects alone, I would subtract the mass of the beaker and the object/beaker combined to fugue out the weight of the object. This was a pretty interesting experiment to be a part of.