What are the chemistry experiments in Nanchang High School Entrance Examination in 2015?

Experiment 1: Preparation, collection and filling of carbon dioxide

Experimental equipment: gas collection flasks (with glass slides), clamps, test tubes, test tube holders, plastic holders iron (with iron clips), single-hole rubber stoppers and catheters, matches, test tube brushes, waste containers and rags.

Experimental drugs: block marble, dilute hydrochloric acid

Steps:

1. Place a large test tube flat, use tweezers to take 2-3 pieces. of limestone and place them at the mouth of the test tube, slowly turn the test tube upwards, allowing the limestone to fall to the bottom of the test tube.

2. Remove the cap from the reagent bottle containing diluted hydrochloric acid, place it upside down with the label facing the palm of the hand, and pour the diluted hydrochloric acid into the test tube (the acid hydrochloric acid should not exceed 1/3of the volume of the test tube), tighten the rubber stopper, fix the test tube on the iron bracket, and fix the iron clamp on the middle and upper part of the test tube (the iron clamp is adjusted). just to fit into the test tube, and the test tube should not be suspended in the air).

3. Insert the catheter into the bottom of the gas collection bottle and cover the mouth of the bottle with a piece of glass (rough side down).

4. After about a minute, place the lit match over the mouth of the gas collection bottle (the piece of glass cannot be completely removed) to check if the collection is full.

5. Pour the waste from the test tube into the waste liquid tank, wash the test tube and insert it upside down onto the test tube rack. Carefully place medicines, instruments, etc., and wipe it clean. clean table.

Others:

1. Use a bottlee with narrow neck to contain diluted hydrochloric acid. (Examine the operation of pouring liquid into the test tube)

2. When collecting carbon dioxide, the piece of glass should be covered with the mouth of the gas collection bottle.

3. When the tube is full, the tube cannot be removed. Just put it in place without waiting for the match to go out.

4. The waste liquid tank cannot be replaced by a sink. (Same requirements for other experiments)

Experiment 2: Filtration of raw salt water

Experimental equipment: funnel, glass rod, iron stand (with iron ring ), filter paper, beaker, wash bottle, test tube rack, liquid waste tank, cloth

Experimental drugs: raw salt water, distilled water

Steps:

1. in half twice and put it into the funnel, hold the filter paper with your fingers, pour a pwater to moisten it and press lightly with the side of the glass rod.

2. Place a small beaker on the iron stand, then place the funnel over the iron ring, with the bottom end of the funnel near the inside wall of the beaker.

3. Place one end of the glass rod on the three-layer filter paper and place the mouth of the beaker containing raw salt water against the glass rod to pour the liquid. The liquid should not exceed. edge of the filter paper.

4. After filtration is completed, place the filter paper in the waste liquid tank and rinse the glass rod and funnel with water.

5. Medicines, instruments, etc. are neatly stored and the table top is cleaned.

Others:

1. The wash bottle is used to wet the filter paper. It is recommended that students equip themselves with this instrument during practice and exams.

2. It is recommendedPlease pay attention to the direction of the funnel when folding the filter paper and inserting it into the funnel.

3. There is no need to wait for all the liquid in the funnel to be filtered during the exam.

4. In order to facilitate the operation of students, the beaker containing raw salt water should not be too large, and the volume should not exceed 30.0 ml.

Experiment 3: Use 5% sodium chloride solution to prepare 50 g of 1% sodium chloride solution

Experimental equipment: beaker, graduated cylinder (10 mL , 50 mL), rubber-tipped dropper, glass rod, test tube rack, test tube brush, liquid waste tank, cloth.

Experimental drugs: 5% sodium chloride solution, distilled water

Steps:

1. First, take a 10mL measuring cylinder and place it on the experimental bench. , then use a beaker to wormPour approximately 8 ml to 9 ml of 5% sodium chloride solution into the graduated cylinder, add up to 9.7 ml dropwise with a rubber-tipped dropper and transfer the liquid from the cylinder graduated in the beaker. (The rubber tip dropper must be cleaned after use before you can use another liquid.)

2. Take a 50 ml measuring cylinder and place it on the experimental bench. Pour approximately 38ml to 39ml of water into the dropper. cylinder and use the rubber-tipped dropper. Add drop by drop up to 40 ml and also pour into the beaker.

3. Stir with a glass rod.

4. Clean the instruments, place them carefully and wipe the table top.

Others:

1. When using the measuring cylinder, pour the liquid into it by hand first, then place it firmly on the table and use a dropper to add the liquid. the required scale.

2. When operating, you can first measure the sodium chloride solution or measure the water.

3. Measure a liquid and pour it into the beaker, or take both liquids and pour them into the beaker.

4. There is only one dropper. Clean it in time after use before absorbing other liquids. (An aspect of correct dropper use)

5. The dropper cannot be placed upside down or flat on the table. Wash it after use and put it in a small beaker.

6. When measuring liquids in this experiment, candidates are allowed to make a mistake using the measuring cylinder. They can pour the liquid into the measuring cylinder and try again if no mistake is made. no points will be deducted.

Experiment 5: Explore some of the chemical properties of acids

Experimental equipment: tweezers, glass rods, test tubes, po standsur test tubes, test tube brushes, waste tanks, rags

Experimental drugs: pH test paper, purple litmus solution, rusty iron nails, diluted hydrochloric acid (contained in a bottle with narrow neck)

Steps:

1. Use tweezers to pick up a stick. Place the rusty iron nail on the mouth of the flat test tube, then slowly straighten the test tube, remove the cap of the diluted hydrochloric acid reagent bottle, place it upside down, with the label facing on the palm. with your hand and pour the diluted hydrochloric acid into the test tube (the mouth of the bottle is close to the mouth of the tube). Diluted hydrochloric acid should not exceed 1/3 of the volume of the test tube).

2. Take another test tube and pour a small amount of diluted hydrochloric acid into it. Take a dry pH test paper and place a dry glass rod into the test tube to dip the amount of ac into it.diluted hydrochloric acid. .

Place it on the pH test paper and compare the color with the standard color card to read (1 or 2).

3. Add 2-3 drops of purple litmus solution to the test tube above (the dropper hangs directly above the mouth of the test tube) and observe the color.

4. Put liquid waste, pH test paper, etc. of both test tubes into the waste liquid reservoir and wash the test tubes, glass rods and other instruments.

5. Medicines, instruments, etc. are carefully placed and the desk is cleaned.clean.

Others: This experiment can be completed with 2 test tubes, and one test tube is reserved. If students do the experiment on the effect of hydrochloric acid and litmus first, they can use the third test tube to finish. measuring the pH value.

1. Put hydrochloric acid in ae narrow neck bottle and pour it into the test tube.

2. During the experiment, just perform the relevant operations, and the measurement results do not need to be reported to the supervisor.

3. Wash the glass rod promptly after use and place it on the test tube rack

I don't have specific experimental steps for the fourth in 2015, but I know it. concerns thin sheets of copper. The author of the experience can find it himself, O(∩_∩)O, please accept and like it

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