9. 172,2 g 1-brompropan yetarli miqdorda olingan natriy metali bilan reaksiyaga kirishganda geksan hosil bo‘ldi. Hosil bo‘lgan geksan massasini (g) aniqlang. Variantlar: 68,8; 94,6; 77,4; 60,2.

Reaksiya Vyurts reaksiyasi bo‘lib, ikki molekula 1-brompropan birikib geksan hosil qiladi:

\(2\mathrm{C_3H_7Br}+2\mathrm{Na}\rightarrow\mathrm{C_6H_{14}}+2\mathrm{NaBr}\).

1. 1-brompropanning molyar massasi: \(M(\mathrm{C_3H_7Br})=3\cdot12+7\cdot1+80=123\) g/mol.
2. Modda miqdori: \(n(\mathrm{C_3H_7Br})=172.2/123=1.4\) mol.
3. Tenglamaga ko‘ra geksan miqdori uning yarmiga teng: \(n(\mathrm{C_6H_{14}})=1.4/2=0.7\) mol.
4. Geksanning molyar massasi \(M(\mathrm{C_6H_{14}})=86\) g/mol, demak \(m=0.7\cdot86=60.2\) g.

Javob: 60,2 g (4-variant).