Ethyne

Question 1

Equation for the preparation of ethyne

Answer 1

CaC2 + H20 = C2H2 + Ca(OH)2

Question 2

What is ethyne also known as?

Answer 2

Acetylene

Question 3

Appearance of calcium carbide?

Answer 3

Grey/Brown solid

Question 4

Why is water added drop wise?

Answer 4

Control rate at which ethyne is formed

Question 5

What is observed in flask during addition of water?

Answer 5

Calcium carbide turns into a white powder and fizzing is noticed

Question 6

Is this reaction exothermic or endothermic?

Answer 6

Exothermic - heat is being released

Question 7

What is the purpose of copper sulfate

Answer 7

Ethyne is bubbled through copper sulfate to remove impurities in gas [hydrogen sulfide, ammonia and phosphine]

Question 8

How are the impurities present in the calcium carbide

Answer 8

Caused by hydrolysis of trades of calcium sulfide, calcium phosphide etc present in calcium di carbide

Question 9

What is the white substance that is formed inside the flask?

Answer 9

Calcium hydroxide

Question 10

Why discard the first test tube?

Answer 10

Consists mainly of air that has been displaced

Question 11

What are the three impurities present in gas

Answer 11

Hydrogen sulfide, phosphine and ammonia

Question 12

Equation when bromine water added

Answer 12

Idk?

Question 13

What happens when ethyne is burned

Answer 13

Smoky luminous flame

Question 14

What is the soot in the flame from?

Answer 14

Unburned carbons

Question 15

Balanced equation for the combustion of ethyne

Answer 15

2C2H2 + 5O2 = 4CO2 + 2H2O

Question 16

Uses of ethyne?

Answer 16

Welding and cutting metals

Question 17

Why can’t calcium carbide be obtained in pure state?

Answer 17

Usually contaminated with calcium sulfide, calcium phosphide and calcium nitrite