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Science Olympiad: Can't Judge A Powder

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michelle y

on 26 September 2013

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Transcript of Science Olympiad: Can't Judge A Powder

Science Olympiad: Can't Judge A Powder
Can't Judge A Powder
Can't Judge a Powder is a chemistry event based on the importance of observation. You as a mad chemist must identify a given powder without burning down the lab!!! During the 50 minutes given, a team of two will perform different tests and answer questions about the powder. The powder may be white or colored and close observations are necessary to answer questions about the powder in a short period of time.
There are a ton of example questions and answers online that will help you prepare. You will feel as if you have been there already! Every time you practice the test try to answer these questions. Here are some examples:
Is the powder soluble in water?
What is the conductivity of the aqueous solution of the powder?
What is the pH of the aqueous solution of the powder?
What is the color of solution formed when the powder
is added to NaOH?
What was the temperature change when the powder was added to the water?
At the Competition
Contestants will be given sample(s) of a substance and they will perform tests using the materials provided.
As chemists, the choice of which tests to do in order to answer the questions is to be determined by YOU.
Various tests will be needed to characterize the powder.
In the first part of the competition, teams will fill out an observation sheet in which the observations should be written neatly and organized (since neatness can affect your score).
At the second part of the competition, teams will use the observation sheet to answer questions about the powder.
Make a table of “Observations” vs. “Inferences” and don’t mix them up! Observations are not conclusions. At the end use both to answer the questions.
Scoring is judged on the quality of the students' answers to the questions about the substance by providing data to support their answers and the quality of the data collected (which is the observation sheet).

By Ariana Dominick,Emerson Connolly, and Michelle Cho
Teams should consist of up to two people.
A white or colored substance is to be examined, but NOT TO identify what the substance is. (Oh no, we only get to be half chemists! Well, we will still be mad chemists!)
Students are allowed to bring only specified items listed. (if you bring any additional items, 10% of your score will drop or you may also be disqualified)
Tests and other items may be provided by the supervisor.
25-35 minutes for testing the powder and 25-30 minutes are given for answering questions about it. The total time will be about 50 minutes approximately.
There are some safety requirements such as wearing goggles.
Scoring Guide

This is an example of how the judges may score you on your observations...
What you may need to know...
How to use different tools such as the conductivity tester, thermometer, pH paper, and much more that is useful and definitely fun!
How to know the difference between inferences and observations.
What a Mole is!!! and how to prepare a solution with a specific Mole.
Know your chemistry! What are NaOH or HCl and what are they used for and why.
How to have team working skills.
How to use your time wisely, while making several observations and tests (since the more observations you have, the more you know in order to answer the questions on the tests).
Being very precise at your observations.
Remembering that solubility, density, and conductivity are inferences based on what you observe, so write down what you see not what you infer.
Powder Chart:
What the observation sheet may look like...
How you can test the powder...
What you can observe...
Control observations are on many tests. Write down everything, even a number on a bottle or a bag, nothing is too un-important to record.
You can observe the powder based on these example questions. In the competition first start out with the basics then write excess information.
Powder: •Luster
Any Liquid: •Color
Adding powder to any liquid: •Did you hear a sound, see bubbles, or smell an odor? Dissolves? How much, how quickly, how easily?
Solution of powder and any liquid: •pH
If a precipitate forms: •Supernate? If so, what color, how much? •What liquid can be added to get rid of the precipitate?

Precipitation is the formation of a solid in a solution during a chemical reaction. When the reaction occurs, the solid formed is called the precipitate, and the liquid remaining is called the supernate.

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