試紙問題

applec

試紙係 chemical 定 physical reaction?

鬼鬼

係Chemical Reaction

Physical Reaction係指風化作用0個D

applec

點解係 Chemical Reaction??
有新的物質形成咩?

幻藍

blue cobalt(II) chloride paper + water-------->pink cobalt chloride paper

pink substance=new substance formed

applec

...咁係你個 example, pink substance 係咩??

oscar

Originally posted by applec at 2005-10-28 15:00:
試紙係 chemical 定 physical reaction?

首先，你的問題已經錯了！
Test Papers本身不會有Reactions，除非它懂得React With Air...

回到正題，Test Papers的Reactions是Chemical的。

鬼鬼

Originally posted by applec at 6/11/05 09:27 PM:
...咁係你個 example, pink substance 係咩??

Litmus ，石蕊囉 [E-TeH]

唔係點解會叫石蕊試紙 :em141:

夢幻蔚藍

試紙係 chemical 定 physical reaction?

<<乜唔係 physical change & chemical change??

dolphin_ice

點會係physical change先?

都冇變形/風化

marcochl

應該係chemical change
用一支火柴做比喻
佢一開始燒就已經係做緊chemical change
因為佢既property 已經change 左(不能再燒)
如果話water(gas form) 的話
雖然佢change左 做gas,但係佢都仲係H2O, 所以唔係chemical change(It only change the form)