... H2S(V/V)≤0.1%9.Molecular weight64.10(according to 1995 international relative atomic mass)10. SIZE4-7,7- ... ,heavy putting down and colliding are not allowed to avoid the spark leads to explosion.Property: Grey, brown or black solid, ... in organic synthesis industry, Acetylene obtanied from calcium carbide is raw material to make ethylene, chloroprene rubber, calcium cyanamide, acetic acd, acetaldehydr, ...