Experiment 8 GAS LAW CHM 420 PDF

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EXPERIMENT 8 CHM 420GAS LAWSSTUDENT NAME SYED MUHAMMAD BASRI BIN SYED MAHMUD SHAHJIHAN (2020869452) NUR AINUN NAZHIRAH BINTI ABDULLAH (2020869962) AISHAH TASNIM BINTI SUHAIMI (2020477214)GROUP AS2222ALECTURER’S NAMEDATE OF SUBMISSIONPURPOSE To verify the Graham’s Law by measuring the distances trave...

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EXPERIMENT 8 CHM 420 GAS LAWS STUDENT NAME

SYED MUHAMMAD BASRI BIN SYED MAHMUD SHAHJIHAN (2020869452) NUR AINUN NAZHIRAH BINTI ABDULLAH (2020869962) AISHAH TASNIM BINTI SUHAIMI (2020477214)

GROUP

AS2222A

LECTURER’S NAME

DATE OF SUBMISSION

PURPOSE

1. To verify the Graham’s Law by measuring the distances travelled during the same period of the time by two different gases of known molecular mass. 2. To determine the molar mass of a volatile liquid by measuring mass of vapour of the liquid is needed to fill a flask of known volume at a particular temperature and pressure

INTRODUCTION In this experiment, two type of experiment is about the gas laws which are Graham’s Law and the determining of molar mass of volatile liquid. For the first experiment, the Graham’s Law, it is about the rate of diffusion of two different gasses. The different gasses have the different density based on their molecules. The both gasses were tested by obtained it from ammonia solution and hydrogen chloride with a higher concentration. Thus, the experiment had to handling in fume hood and wearing the safety kits to ensure the safety. The product of reaction between the gasses showed will appeared as white ring and the different of product’s distance between the two gasses indicated which one of the gasses are more and less dense. The indication of the density based of the distance of white ring to the both gasses. Meanwhile, which are more closes and far from the white ring formed.

In this experiment, the gasses used are ammonia gas and hydrogen chloride gas therefore the product produced is ammonium chloride. The rate of diffusion for both gasses was determined by calculating the molar mass and rate for both gasses. For the determining of molar mass of volatile liquid experiment, the unknown volatile liquid was used to be tested. Related to the ideal gas law which is the gas law could be used to define mole of the unknown volatile liquid. Thus, the mole was used to indicate the real molar mass of the unknown volatile by multiply the mole with mass of condensed vapour of the unknown solution. From that molar mass, the identity of the unknown volatile could be known. The experiment was handed by placed the unknown volatile into the flask with known volume. Next, the flask will be heated using boiling water bath also had been mixed with some boiling chips in the flask. The boiling chips is for prevent the boiling of the volatile solution to be so aggressive.

The heating for ensure the volatile liquid fully dry and proceed with the next step. The determining of the mole is based on the ideal gas law as below: n= PV/RT derived from PV= nRT n = molar mass / mass Therefore, in order to define the mole of the unknown volatile liquid, the volume of vapour and the temperature used to drying the volatile liquid must be known first.

CHEMICALS AND APPARATUS NH3 (conc.)

Stopper

HCl (conc.)

Medicine dropper

Acetone (to dry the glass tube)

Tweezers or crucible tongs

Retort stand

Stopwatch

Glass tube (50cm length, 10 mm internal diameter)

Marker pen

Cotton

Long stand (1 meter)

Boiling chips

Retort stand

Unknown volatile liquid

400/500mL beaker

Bunsen burner

100/125 conical flask

Pin (to make a hole)

500 mL graduated cylinder

Thermometer Aluminium foil

PROCEDURE

A. Graham’s Law 1. A 50 cm length of glass tubing was obtained. Ensure it is totally dry and prepared two cotton swabs. 2. Using dropper pipettes, 25 drops of concentrated HCl was placed on the cotton swab and 25 drops of concentrated NH 3 on another cotton swab. 3. Using tweezers, the moistened end of the cotton swabs were inserted into opposite ends of the tube. The time needs for the appearance of the faint white cloud (ring) of ammonium chloride gas noted. 4. After several minutes, a white ring is formed. The point in the tube where the white ring is formed was marked. The distance travelled by each gas was measured. The data recorded. 5. The cotton swabs were removed using tweezers and immersed into a beaker of tap water. 6. The tubing was rinsed with water and dried using acetone.

B. Molar Mass of Volatile Liquid 1. A boiling water bath was set up using 400 mL beaker containing 250 mL of water. 2. Boiling chips was added into a conical flask. The mouth of conical flask was tightly covered with a small square of aluminium foil and a small hole was made on the foil cap. 3. The empty capped flask was weighed together with boiling chips. 4. The foil cap was removed. A 2 mL sample of the liquid was placed and the foil was replaced. 5. The flask was clamped with a single burette clamp. The flask was transferred to the boiling bath, immersed and heated. 6. The liquid refluxing inside the flask was noted. The flask was slightly titled.

7. The heating is continued until liquid is no longer visible and no vapour can be seen emerging from the pinhole.

The heating was continued 30

seconds beyond this time. 8. The flask was removed and place on a tile. The clamp was removed and the flask was cooled it on the room temperature. 9. The flask was dried and weighed the flask, cap and condensed vapour. 10.The contents of the flask was disposed in waste bottle. The flask was filled with tap water and poured into a 500 mL graduated cylinder. The volume was measured and recorded....