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laboratory preparation of methane

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Answers:You should have been able to find this in any good organic chemistry text. The number of methods makes listing each one too long for the format of this forum. The sites below should give you all of the information that you need:

Question:1. why is it necessary to fire polish freshly cut ends of glass tubing? 2.why must glass rod or stirring rod be closed at both ends? 3. why is a wing top necessary when heating a glass tubing for preparing bends? 4. can you give some precautions to be followed in inserting a glass tubing through the hole of cork or rubber stopper? 5. why is the glass tubing need to be removed slightly away from flame while bending?

Answers:1. To make it safer to handle and eliminate microcracks in the glass 2. This only applies to a stirrer made from tubing. Both ends are closed so that liquid cannot get into the tube and create cross-contamination 3. It spreads the flame so that the tube does not collapse at the bend point but instead bends smoothly over a greater length 4. PROTECT YOUR HANDS! If the tube breaks you could spear yourself. Fire polish the ends of the tube and lubricate with water or glycerin. Hold cork. stopper and tubing with towel.Rotate back and forward as you insert the tube. See Google Books: http://books.google.com/books?id=89w4kyQqQXcC&pg=PA394&lpg=PA394&dq=insert+glass+tubing+cork&source=web&ots=5paqHZ5oCI&sig=B771qMdINPyy6lqZoN0R_BCNreQ&hl=en&sa=X&oi=book_result&resnum=6&ct=result 5. To let it cool a little. Bending while still in the flame increases the possibility of collapsing the tube.

Question:... clay triangle ... iron clamp ... difference of hard glass test tube and ordinary test tube ... crucible tongs ... water trough ... water bath ... crucible and cover ... mortar and pestle i need answers in 20 minutes haha

Answers:Clay triangle- It is used as a base to keep some apperatus(e.g. beaker,flask, etc.) on it while heating them. IF we keep apparatus directly on sand bath then the tem. will not uniform & also the apparatus will get break. due to the clay tringle. apparatus will get uniform heating surface as well as remain protected as it is not in direct contact with sand. Diff in Hrad & ordinary Tubes? The material of which it is made of create a difference in their properties.The so called hard contain greater % of silica so that it remain intact even on heating to a higher temp.as it has high resistance.On the contarary the ordinary test tubes are not meant to be heat at higher temp.(above 70 C) as they may get broken up. They are only for pbserving the reactions. a so the hard one also called as Borosil test tubes ar costlier. Water Bath- It serves the simple purpose of not to heat the substance above !00 C i.e. the boiling point of Water. It is use for control temp. reactions.(practically it gives temp. of upto 90 c only) Crucible & cover- It has the many uses. Basically it is used for heating the substances at very higher temp. & cover is simply to avoid any loss of material as well as to prevent external material to enter in.(for quantitative measurments) Mortar & pestle- It is same as the crusher which we use at home to prepare chutny and spices .it has the basic purpose of grinding or mixing the substances very finely,


Answers:Here's what I think the answer is: Acyl chloride's functional group is -COCl while carboxylic acid has -COOH Acyl chloride is very reactive because of the chlorine on the C=O (carbonyl carbon) which makes the structure very electronegative. Electronegativity is the ability of an atom to attract electron density towards itself (thus making it a very good electrophile). Carboxylic acids are polar and forms hydrogen bonding. If you compare the reactivity of this two, then acyl chloride is the better reagent because of the chlorine which in a way activates the the carbonyl group due to increased electronegativity. Hope this helps.. Ciao

From Youtube

Hydrogen Laboratory Preparation :A sample of hydrogen gas may be prepared in the lab by the action of dil hydrochloric acid on magnesium ribbon. (CAUTION - Danger of Explosion and severe personal injury. Ensure there are no naked flames if the reaction is done on any scale greater than a single test tube.) This clip shows the use of a thistle funnel. On adding acid solution the acid solution must cover the bottom of the funnel down tube. (Caution - Danger of glass cuts. Make sure you know how to fit glassware to bungs. ) Thistle funnels used in this way provide a indication of the pressure in the reaction flask by the level of acid in the down tube of the funnel. Tap funnels do not warn the user of an unwanted build up of pressure in the reaction flask. If a sample of hydrogen collected in a test tube is very pure (the reaction is allowed to run to flush out any air before the collection) and 'tested' by a lighted flame, the 'pop' is never squeaky, and is rather disappointing. See ChemPics 'Testing for Hydrogen'.

Solution Preparation :Method and techniques for preparing a dilution solution of manganese from potassium permanganate. NAIT Chemical Technology Laboratory Technique series