Chem Lab

EPHS - Nicholas

Chemistry Period 4

February 16, 2006

Introduction:

The purpose of this lab is to identify and record data that shows how heat is involved in chemical change. Also, to explain why a substance can be either a reactant, or a product in a chemical change. Finally, to learn why it is necessary for recycling.

Method:

In the laboratory, students were to complete a number of chemical reactions by adding certain chemicals to Copper (II) Nitrate, ultimately turning it back into copper.

Materials:

Pyrex test tube 13 ÐŽÐ' 100 mm

100 ml beaker

Burner and tubing

Ruler

Lab marker

Stirring rod

Iron ring

Ring stand

Wire gauze, ceramic centered

Test tube rack

1.0 M copper(II) nitrate

1.5 M hydrochloric acid

1.5 M sodium hydroxide

12 cm piece of aluminum wire

Safety Note:

Sodium hydroxide is a caustic and corrosive substance. Be certain to wear safety goggles, apron, and gloves. Avoid contact with skin and eyes. Avoid breathing vapors. If any of this solution should spill on you, immediately flush the area with water and notify your teacher.

Procedure:

(Record your observations in the Data Table)

In the 100 ml beaker, make a water bath by heating until boiling approximately 50 ml of water. This will be used in Step 5

While the water bath is heating make three marks that are 1 cm apart on a 13 ÐŽÐ' 100 mm test tube. Make the marks from the bottom up.

Add 1.0 M copper(II) nitrate to the first mark on the test tube

Add 1.5 M sodium hydroxide to the second mark on the test tube. Mix with the stirring rod. Rinse the stirring rod. Touch the bottom of the outside of the test tube to see if heat has been released. The copper containing product is copper (II) hydroxide. The other product is sodium nitrate.

Put the test tube in the water bath begun in Step 1. Heat it until no more change occurs. The products are copper (II) oxide and water.

Remove the test tube from the hot water bath. Turn off the burner. Cool the test tube and its contents for 2 minutes in room temperature water. Add 1.5 M hydrochloric acid to the third mark. Mix with the stirring rod. Rinse the stirring rod. The products are copper (II) chloride and water.

Place a 12 cm piece of aluminum wire in the test tube. Leave it until no more reaction is observed. Touch the bottom of the test tube to check for temperature change. Two reactions take place. Copper (II) chloride and aluminum produce copper and aluminum chloride. The aluminum also reacts with the hydrochloric acid to form hydrogen and aluminum chloride.

Remove the wire from the test tube. Compare the copper formed to a sample of copper wire.

Dispose of the solids and the liquids formed in the experiment as your teacher directs. Empty the water from the hot water bath. Clean all equipment used. Remember to wash your hands before you leave the laboratory.

Results:

Data Table 1

Reactants Products Observations of Products

Precipitate (Solid) Supernate(Liquid)

Copper(II) nitrate

(blue solution)

+

Sodium hydroxide

(colorless solution)

Copper(II) hydroxide

+

Water

None Visible Opaque, vivid aqua coloration/Very thick, almost gel like. Mixture cooled a bit

Copper(II)

hydroxide

+

(heat)

Copper(II) oxide

+

Water

Brownish-Black substance forming at bottom of test tube Transparent, clear, quite pure looking

Copper(II) oxide

+

Hydrochloric acid

Copper(II) chloride

+

Water

Liquid is semi- opaque. Brownish ЁC Black in color. Lustrous material settling at bottom of test tube. Heat of mixture rose a small bit.

Aluminum

+

Copper(II) chloride

Copper

+

Aluminum

Chloride

Lustrous Material at bottom Transparent, blue-tinged liquid bubbles beginning to rise.

Aluminum

...