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Physical And Chemical Change Lab Report

Decent Essays

***SAFETY PROCEDURE*** WEAR YOUR SAFETY GOGGLES AND APRON.
PHYSICAL AND CHEMICAL CHANGES

Purpose: In this experiment you will observe some physical and some chemical changes. You will observe that energy must be used to start some chemical reactions, and that it is produced in others.

Apparatus: Forceps Bunsen burner Funnel Wire gauze Crucible tongs Filter paper Test tubes, large and small Universal clamp Test tube rack Stirring rod Ring stand and ring Materials: Nichrome metal Magnesium metal Wooden splints Sodium chloride solution, NaCl, 0.1 M Hydrochloric acid, HCl, 3M Silver nitrate solution, AgNO3, 0.1M Steel wool Sodium hydrogen carbonate, NaHCO3, solid Zinc metal, Zn

Theory: Matter …show more content…

Procedure:
For each step record observations and conclusions in your data table.

l. NICHROME - APPEARANCE AND REACTION TO HEAT Examine a piece of nichrome wire. On the data sheet, record the color and the luster of the metal. Use a forceps to hold the wire in the flame of your burner for about two minutes (recall where the hottest part of the flame is located). Describe the appearance of the wire while held in the hottest part of the flame. Allow the wire to cool and reexamine it. From your observations, determine if there was a physical or a chemical change. Give specific reasons for your conclusions. Save the nichrome wire for step #2.

2. NICHROME - REACTION WITH ACID
***SAFETY PROCEDURE*** HYDROCHLORIC ACID IS A CORROSIVE SUBSTANCE WHICH CAN CAUSE DAMAGE TO SKIN AND OTHER SUBSTANCES. IT HAS STRONG VAPORS. WEAR GOGGLES AND AN APRON. YOUR TEACHER WILL SHOW YOU HOW TO POUR THE ACID SAFELY. IF YOU SPILL ACID ON YOURSELF, WASH IT OFF WITH LOTS OF RUNNING WATER. A FEW DROPS SPILLED ON THE LAB BENCH CAN BE CLEANED UP WITH A PAPER TOWEL. A LARGE SPILL SHOULD BE NEUTRALIZED WITH BAKING SODA, AND THE RESULTING NEUTRAL SUBSTANCE CAN THEN BE WASHED INTO THE SINK WITH A …show more content…

Give specific evidence for your conclusions.

1. Nichrome and heat The nichrome wire is silver with a sort of rusty brown color on portions of it and is not slightly shiny. When the nichrome wire was put into the heat (bunsen burner), the flame turned from blue to orange, and the wire began glowing orange in the part touching the flame. This was a physical change because the only thing that changed was the color was changed but went back to normal, thus indicating that the composition has not changed.

2. Nichrome and hydrochloric acid The nichrome wire exposed to the acid there was nothing that occurred. Therefore, it was neither a chemical nor physical change.

3. Zinc and hydrochloric acid When the zinc was dropped in the hydrochloric acid, the substance began bubbling vigorously, forming a precipitate. Eventually, the zinc dissolved completely. After the lit wooden splint broke the surface of the test tube, there was a loud popping noise. The gas that was released was hydrogen from the acid and the popping noise was a result of the Hydrogen being burned up by the fire creating a small explosion. Two chemical changes occurred in this test: one with the formation of a precipitate (a textbook sign of a chemical change), and the other when the explosion

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