Experimental Activity 1 Laboratory Preparation and Properties of Oxygen

Experimental Activity 1

Laboratory Preparation and Properties of Oxygen

Purpose

1.Learn how to make oxygen in the laboratory.

2.Gain a better understanding of the properties of oxygen.

Experimental supplies

Large test tube, single-hole rubber stopper, rubber tube, iron clip), alcohol lamp, glass piece, ground cochlear forceps, potassium permethate, charcoal, clarified lime water.

Experimental steps]

1.produce oxygen

(1)Take a closer look at the device shown in Figure 2-17 . What instruments are used? Which part is the gas generator? Which part is the gas collection device? Why can oxygen be collected by drainage method?

(2)Seal the test tube with a rubber stopper with a guide tube to verify the airtightness of the device. After confirming that the device is not leaking, pull out the rubber stopper, put a small amount of potassium permethate into the test tube, put a ball of cotton at the test tube mouth, plug the tube mouth with a rubber stopper with a catheter, and turn the test tube mouth slightly downward.

(3)Fill the two gas-collecting bottles with water respectively, cover the mouth of the bottle with a glass piece, then place the gas-collecting bottle full of water upside down together with the glass piece in the sink filled with water.

(4)Heat the test tube. Put the flame of the alcohol lamp under the test tube

Move it back and forth so that the test tube is heated evenly, and then heat the part where the potassium peroxide is located.

When bubbles start to be released from the catheter mouth, it is not advisable to collect them immediately. When the bubbles are released continuously and relatively uniformly, extend the catheter mouth into a gas bottle filled with water. After the water in the gas collecting bottle is drained, cover the mouth of the bottle with a piece of glass under the water surface. Carefully remove the gas bottle from the sink and place it on the table. Use the same method to collect another bottle of oxygen (a small amount of water is left in the bottle).

(5)When stopping heating, first move the catheter out of the water, and then turn off the alcohol lamp.

2.properties of oxygen

(1) As shown in Figure 2-18 , take a small piece of charcoal with ground cochlear forceps, heat it on an alcohol lamp until it turns red, insert it into the oxygen collected in the above experiment (insert slowly from the mouth of the bottle), and observe The burning of charcoal in oxygen. After the combustion stops, take out the ground worm pliers, add a small amount of clarified lime water to the gas collecting bottle, and shake it. What happened?

(2) Light the match attached to the bottom of the spiral thin iron wire. When the match is almost burned out, insert it into the gas collecting bottle filled with oxygen (a small amount of water is added in the bottle in advance). Observe how iron wire burns in oxygen.