個個人既答案都唔同...信邊個好=.=
總知邊個都唔好信啦
總知邊個都唔好信啦
Zend 發表於 11-4-2009 15:27 http://www.nakuz.com/bbs/images/common/back.gif
點解唔講下係咩
唔通無一個標準答案?
點解唔講下係咩
唔通無一個標準答案?
lkhj2525 發表於 12-4-2009 00:47 http://nakuz.com/bbs/images/common/back.gif
我只係知你地講的係錯－。－
我無義務講答案
會考試過淨係俾concentration而冇提佢係con.定dilute-.-
screen 發表於 10-4-2009 21:04 http://www.nakuz.com/bbs/images/common/back.gif
多數- -v
好似chem03 LQ 9a(iii)
2M nitric acid
都唔知係dilute定conc
佢又叫考生寫條equation出黎
需知metal同HNO3 react出乜要睇concentration
我做個時都唔知點算
本帖最後由 Roy 於 12-4-2009 15:05 編輯
小弟相信樓主應該對於
這三種HCl. H2SO4, HNO3. acid, 怎分幾時dilute幾時conc. ,應該心中有數,
如版主所言,dilte及conc.其實只是比較而已
數字上,幾多M才是dilute幾時conc. 無需分得太清。
==
回樓主「搭單」問的「點解oil spillage on the sea唔可以用soap整走」
我想知樓主說的Soap在你原本的問題中會不會是指為Soapy detergents?
acid幾M先conc?
HCl. H2SO4, HNO3.
HNO3幾時very dilute幾時dilute幾時conc -.-?
順帶一問. 點解oil spillage on the sea唔可以用soap整走 ._.?
因為biodegradable所以favourable to micro-organisms -.-? ...
7ond 發表於 10-4-2009 18:53 http://www.nakuz.com/bbs/images/common/back.gif
有scum
本帖最後由 李靂 於 12-4-2009 17:11 編輯
HKCEE chem03 LQ 9a(iii)
In an experiment, a piece of brass(copper and zinc compound) is added to a test tube containing 2M nitric acid.
State TWO observations in the experiment and write the relevant chemical equation(s).
observations無論dilute定conc都係
1)brown gas form2)solution change to blue in colour
但equation寫咩?
dilute既...先出NO再同O2 react出NO2
conc既...直接就出NO2
呢條係dilute定conc?
係wor有scum 囧rz..(跳樓
其實主要問題係驚到時唔知佢conc定dil o個d -.-
sulphuric acid 同 nitric acid要睇concentration先知反應嘛 -.-"
好啦唯有望佢講清楚.