Introducing
Your new presentation assistant.
Refine, enhance, and tailor your content, source relevant images, and edit visuals quicker than ever before.
Trending searches
Preparation and Properties of Methane
200
Preparation and Properties of Methane
THANK YOU!
Von Baeyer's Test
It is a test used in organic chemistry as aqualitative test for the presence of
unsaturation, such as double bonds.
Baeyer's reagent is an alkaline solution of cold potassium permanganate, which is a powerful oxidant making this a redox reaction
Observation:
Saturated hydrocarbon cyclohexene + bromine → dissolve
(yellow to brown coloration)
Unsaturated hydrocarbon cyclohexene + bromine → disappear (white coloration)
Materials
Bromine Test
Materials
Equation:
H2=CH2 → H2 BrC - CBrH2
Transfer about 10 mL of methane into a test tube and immediately add 1-2 drops of bromine water then blow across the mouth of the tube.
Hold a piece of moistened blue litmus paper to the fumes that evolved. Do not allow the litmus paper to touch the sides of the tube.
Reagents
Von Baeyer's Test
Place about 10 mL of methane to another tube and add 3.0 mL of dilute potassium permanganate solution. Cover and shake, taking care not to allow the mixture to be in contact with the cork.
Flammability and Products of Combustion
Observation: It produced blue non-sooty flame.
Eq: CH42O2 → CO2 + 2H2O + heat
Preparation of Methane
Thoroughly grind together in a mortar 10 g of soda lime and fused sodium acetate. Place the mixture in a hard glass tube. Tape the tube in order to leave an air space above the mixture. Fit into the mouth of the tube a one-holed stopper through which obtusely-bent glass tubing has been inserted. Attach a rubber tubing to serve as a delivery tube for the collection of gas by water displacement method. Mount the tube on an iron stand as shown in the figure. Keep the tube inclined so that its mouth is a little lower than the close end.
Heat the tube keeping the flame in motion. Allow the first bubbles to escape as it is the displacement of most of the air in the apparatus. Collect four test tubes of the gas.
After the required amount of methane has been collected lift the delivery tube from the water and then light or ignite the issuing gas. Burn the gas for a minute and then remove the flame from the generator.
Methane
Equation:
CH3COONa(s) + NaOH(s) → Na2CO3(s) + CH4(g)
Properties of Methane
• Color: Colorless
• Odor: Odorless
-a colorless and odorless gas which burns with a faintly luminous flame
-formed by the decomposition of vegetable matter under water in marshy regions, hence called "marsh gas"
-found in coal mine, where it is a great source of danger because it forms explosive mixtures with air
- Miners call the gas “fire damp” methane is the principal constituent of natural gas and is one of the important ingredients present in most fuel gases.
-a relatively non-toxic; it is a simple asphyxiant. It is flammable in air and forms explosive mixtures with air.
Learning Outcomes
The students must have:
produce methane
tested for the properties
of methane gas