本帖最後由 Hinton 於 15-4-2009 03:47 編輯
29# 李靂
其實條題目需要少少既邏輯推斷同知識
邏輯推斷:一定唔會係very dilute acid
因為可以reacts with copper
就點都冇可能係咁既concentration啦...
而2M 呢個數字...以我地既普遍理解
都唔會將佢當做conc acid...
因為細心既人應該會喺introduce acid and alkali個課
略略知道比較客觀既標準---各個酸既濃度去到邊度,先叫conc.
29# 李靂
其實條題目需要少少既邏輯推斷同知識
邏輯推斷:一定唔會係very dilute acid
因為可以reacts with copper
就點都冇可能係咁既concentration啦...
而2M 呢個數字...以我地既普遍理解
都唔會將佢當做conc ac ...
Hinton 發表於 15-4-2009 03:46 http://www.nakuz.com/bbs/images/common/back.gif
2M HNO3係dilute
但係2M既salt solution例如NaCl就係conc. -.-
點分?
我阿SIR話會考一定唔考- -..佢一定寫明係dilute定conc.
32# screen
呢層你可以放心
CE一定會將個concentration強調得好清楚
因為salt conc/dilute 喺electronlysis個陣...anode都會出chlorine
佢個身份好尷尬,因此考評局會好小心set呢d數字,而且會考慮到考生有冇能力理解個濃度;
所以一係大約0.0xM 度..佢會特登將個數字整細,畀d考生知個concentration程度去到邊;
其餘好似你咁講2M 就叫dilute(唔係very dilute)/conc咁
所以,做題目之前...一定要望清先好落筆- -"
For HNO3
conc = can be O.A with product NO2 released
dilute = can be O.A with NO released [ 1~2M ]
very dilute = shows acid property only [ <1M normally in rtp]
For H2SO4
96% in water is the most concentrated in rtp
O.A property shown = conc
For HCl
mist released = conc / reducing property shown = conc
This is my method of memorization
For HNO3
conc = can be O.A with product NO2 released
dilute = can be O.A with NO released [ 1~2M ]
very dilute = shows acid property only [
小莓。改 發表於 18-4-2009 11:18 http://nakuz.com/bbs/images/common/back.gif
終於等到人講真野
其實濃定唔濃,唔關乜野定限濃度事,果D 只係經驗主義,上唔到大堂
其實濃定唔濃,係看佢做唔到係"濃"GE 情況下做到的東西（不過果個濃唔濃都係相對的野）
當然你話其他稀濃都一樣的時候,點先叫濃,就係相對GE JEI.
不過飽和情況可以作為一個REFERENCE
NaCl RTP 最多係36.0g/100mL
NaCl is 58.0g /mol so , 其實佢最大可能都係
(36.6/58)/0.1 = 6.31M
硝酸有１５定１６Ｍ
本帖最後由 aildux 於 18-4-2009 15:13 編輯
36# Zend
你咁咪即系無答
react完你先知conc唔conc 識chem既人都識啦
但系依家條問題系俾你某個concentration然後叫你寫reaction啊, 唔系react完問你conc唔conc啊.
36# Zend
你咁咪即系無答
react完你先知conc唔conc 識chem既人都識啦
但系依家條問題系俾你某個concentration然後叫你寫reaction啊, 唔系react完問你conc唔conc啊.
aildux 發表於 18-4-2009 15:12 http://nakuz.com/bbs/images/common/back.gif
我都無話要去答佢，我只係表達我意見ＪＥＩ
To #37
用個類比先
如果我同你講放水在150度中, 佢係咩STATE?
同樣道理, 如果我同你講硫酸40M, 佢算CONC定唔CONC
39# 小莓。改
如果我同你講放水在150度中, 佢係咩STATE?depends on pressure
同樣道理, 如果我同你講硫酸40M, 佢算CONC定唔CONC 你整支30M來先講啦....40M好離譜者