Flashcards in Ethyne Deck (17):
Equation for the preparation of ethyne
CaC2 + H20 = C2H2 + Ca(OH)2
What is ethyne also known as?
Appearance of calcium carbide?
Why is water added drop wise?
Control rate at which ethyne is formed
What is observed in flask during addition of water?
Calcium carbide turns into a white powder and fizzing is noticed
Is this reaction exothermic or endothermic?
Exothermic - heat is being released
What is the purpose of copper sulfate
Ethyne is bubbled through copper sulfate to remove impurities in gas [hydrogen sulfide, ammonia and phosphine]
How are the impurities present in the calcium carbide
Caused by hydrolysis of trades of calcium sulfide, calcium phosphide etc present in calcium di carbide
What is the white substance that is formed inside the flask?
Why discard the first test tube?
Consists mainly of air that has been displaced
What are the three impurities present in gas
Hydrogen sulfide, phosphine and ammonia
Equation when bromine water added
What happens when ethyne is burned
Smoky luminous flame
What is the soot in the flame from?
Balanced equation for the combustion of ethyne
2C2H2 + 5O2 = 4CO2 + 2H2O
Uses of ethyne?
Welding and cutting metals