0标4化对 Acetylene Acetylene is used in welding torches. In pure oxygen,temperature of flame reaches 2800C. It would violently decompose to its elements,but the cylinder on the torch contains crushed firebricki耐火砖粉末wet with acetone to moderate it
Acetylene ◼Acetylene is used in welding torches. ◼In pure oxygen, temperature of flame reaches 2800C. ◼It would violently decompose to its elements, but the cylinder on the torch contains crushed firebrick耐火砖粉末wet with acetone to moderate it
自秋标特试 Sec 1 Structure and Properties Nonpolar,insoluble in water. Soluble in most organic solvents. Boiling points similar to alkane of same size. Less dense than water. Up to 4 carbons,gas at R.T
Sec 1 Structure and Properties ◼Nonpolar, insoluble in water. ◼Soluble in most organic solvents. ◼Boiling points similar to alkane of same size. ◼Less dense than water. ◼Up to 4 carbons, gas at R.T
自秋特大材 Acidity of Alkynes Terminal alkynes,R-C=C-H,are more acidic than other hydrocarbons. Acetylene -acetylide by NH2,but not by OH-or RO-. More s character,so pair of electrons in anion is held more closely to the nucleus. Less charge separation,so more stable
Acidity of Alkynes ◼Terminal alkynes, R-CC-H, are more acidic than other hydrocarbons. ◼Acetylene → acetylide by NH2 - , but not by OH- or RO- . ◼More s character, so pair of electrons in anion is held more closely to the nucleus. Less charge separation, so more stable
自秋不转大对 Acidity Table 中院 TABLE 9-2 Compound Conjugate Base Hybridization s Character pKa HH HH weakest H-C-C-H H-C-C© D3 25% 50 acid HH HH H、 H C=C H H p2 33% 44 :NH2 (ammonia) 35 H一C三C一H H一C=C© p 50% 25 stronger R一OH R-0: (alcohols) 16-18 acid
Acidity Table
R一C=CH (pKa-25) 酸性 pka 乙炔 25 乙烯 36.5 H' 乙烷 42 相对酸性： H20 >ROH>CH≡CH > NH> 共轭碱的相对碱性： OH <OR<CH≡C<NH2<R
R－C≡CH （pKa=25） 酸性 pka 乙炔 25 乙烯 36.5 H+ 乙烷 42 相对酸性： 共轭碱的相对碱性：