Question 36
Hydrogen, Oxygen and OxidesHydrogen is used in oxy-hydrogen flames for melting metals because it
- A.evolves a lot of heat when burnt
- B.combines explosively with oxygen
- C.is a very light gas
- D.is a rocket fuel.
Show the answer and explanation
Answer: A (evolves a lot of heat when burnt)
Explanation
Burning hydrogen in oxygen releases a great deal of heat, giving a flame hot enough to melt and weld metals.