- - chemical equipment;
- - catalysts;
- - bromine water.
acetylene, ethylene and ethane - normally colorless flammable gas.So first read the safety precautions when working with volatile substances.Do not forget to repeat the structure of molecules and chemical properties of alkynes (unsaturated hydrocarbons), alkenes and alkanes.Let's see what they look like and what is the difference.For ethane you need acetylene and hydrogen.
to produce acetylene in the laboratory, perform the decomposition of calcium carbide CaC2.It can take prepared or obtained by sintering
with coke burnt lime: CaO + 3C = CaC2 + CO - process takes place at a temperature of 2500 ° C, CaC2 + 2H2O = C2H2 + Ca (OH) 2.Conduct quality response to acetylene - discoloration of brominewater or a solution of potassium permanganate.
produce hydrogen, you can with several ways: - the interaction of metals with acid: Zn + 2 HCl = ZnSl2 + H2 ↑ - during the reaction alkali metal hydroxides, which have amphoteric properties: Zn + 2 NaOH +2 H2O = Na2 [Zn (OH) 4] + H 2 ↑ - electrolysis of water to increase the conductivity of which is added an alkali.When this hydrogen is generated at the cathode and at the anode - oxygen: 2 H2O = 2 H2 + O2.
For of acetylene ethane necessary to carry out the addition reaction of hydrogen (hydrogenation), taking into account the properties of chemical bonds, first of ethyl acetylene, and then with further hydrogenation - ethane.For a visual expression processes compose and record the reactions: C2H2 + H2 = C2H4C2H4 + H2 = C2H6Reaktsiya hydrogenation proceeds at room temperature in the presence of catalysts - finely divided palladium, platinum or nickel.
When working, observe safety.Remember that these gases burn well and when mixed with air or oxygen are explosive.
Note that hydrogen is lighter than air, so it is necessary to collect in the tube turned upside down.Determine the production of ethane, you can by subjecting it to bromine water (its coloring will remain unchanged).