高手入黎幫我清清d問題

[H]bunbunbunbun

1. dipole attraction係唔係intermoleculer force?
2. theoretically Na 同Ca 邊個可以displace邊個?
3. gamma-Al2O3點解唔會有alpha-Al2O3 0既保護作用?
4. in addition polymerization, 係唔係用左catalyst, d molecule就一定會同一個方向polymerize?
i.e.
nC2H3Cl--->---CH2CHClCH2CHClCH2CHCl---
而唔會
nC2H3Cl--->---CH2CHClCHClCH2CH2CHCl---

5. In eletrolysis of molten Al2O3,
why use graphite anode when oxygen will oxidize the rods?
Because other materials will melt/be oxided as well?


聽日溫哂會再加多d問題
幫幫手唔該....

[ 本帖最後由 [H]bunbunbunbun 於 27-4-2008 11:56 編輯 ]

Zend

原帖由 [H]bunbunbunbun 於 27-4-2008 04:26 PM 發表
我老師好熱心教好多out sy 野-,-

係H-Cl入面
H係+ve, Cl係-ve
咁H同另一個HCl入面0既Cl就有一個attraction
呢個係dipole-dipole attraction

H 係slightly positive, Cl 係slightly negative <= due to EN difference
所以個bonding e- cloud 係partly shift towards the internuclear axis of Cl  => permanent dipole is formed
同adjacent molecules , 有相反charge 的attraction 係叫permanent-dipole permanent-dipole interaction/ attraction
佢d molecules 比較自然會oriented 去一個form in which repulsion is minimized + attraction is maxmized ..

舊out-c 野, 都幾好, 我個人認為, 有d 招式係幾好用for CE

[H]bunbunbunbun

我老師好熱心教好多out sy 野-,-

係H-Cl入面
H係+ve, Cl係-ve
咁H同另一個HCl入面0既Cl就有一個attraction
呢個係dipole-dipole attraction

piyopiyo

咩叫dipole attraction
點解會無教過[[tk_02]]

Zend

科學家未有定論
但一般做catalyst 都係transition metals
佢地可以幫手增加effective collisions, 包括拉近molecules 距離 by adsorption
包括weaken 兩隻的bond,(e.g. in Haber process, 最難過係N2->2N ne 個我地叫rate-determining step 的東東,因為N三N太難break)  包括有low-lying vacant d orbitals 去比佢attract ,甚至係做electron transfer , 一切都係等你讀A-level 先看

PVC 同VC 唔同chemical properties
你驚係驚佢有d unpolymerized ge VC 殘留係表面, 又或者佢會分解
raincoat / aritifical ge leather 做的手袋都唔係好驚
PVC 通常做drain water ge pipe, 如果做drinking water 我信是比較少

IUPAC, 無記錯相同數字... 時候, 我估係-2-ol好d

Na, 你燒佢都基本上出d Na2O2 出來,
但pure oxygen or high conc of O2 ,加熱效果更佳

piyopiyo

For alkanols...the smaller number is given to the C which bonds with OH[[tk_36]]

[H]bunbunbunbun

回復 5# 的帖子
嗯嗯...
唔該哂

-------------
可唔可以概括咁講下catalyst點provide alternative activation energy?

IUPAC name of CH3CH(CH3)CHOHCH3
係3-methylbutan-2-ol定2-methylbutan-3-ol ?
(個numbering preference係點分?)

PVC既然係poisonous
做raincoat/handbag唔會對人體有害咩?

係唔係燒Na時有plentyful O2就出NaO2
一般就出Na2O2
少就出Na2O
??

[ 本帖最後由 [H]bunbunbunbun 於 27-4-2008 15:44 編輯 ]

Zend

原帖由 octopus001 於 27-4-2008 03:16 PM 發表
唔係O2 會attack carbon electrode ga咩?
我唔知睇咩睇返黎ga wo 一.一

等我又引用[YU] 果句:

不要問, 只要信[[tk_36]]

octopus001

唔係O2 會attack carbon electrode ga咩?
我唔知睇咩睇返黎ga wo 一.一

Zend

1. intermolecular forces 入面的van der Waals' forces 先係有
dipole-dipole
dipole-induced dipole/induce dipole-dipole
instantaneous -induced dipole
ion-dipole(water+Na+ , water +Cl-)2. 你了解下E.C.S 點來就知有無可能發生=.=
theoretically, Na replaces Ca2+.
3.這個同問graphite Vs diamond, 點解diamond 要極高溫(700-900'C, 某程度上要加壓)先燒到佢變CO2, 而charcoal , graphite 係in an order of ascending flash pt ...
4. 這個是AL 的free radical addition reaction,涉及左radical ge stability, 這點我信唔會係CE 考=.= 過多1,2年再學啦
5. 係用graphite, 你唔好擔心佢電流過大/會被oxidized 問題 =~=
知個process 就得