20分 高手請入~ F.3 chemistry

solubility is the physical properties!!! after remove the solvnet by heat. it will

return to its solid state. if a matter change in its chemical propertie, its

physical properties (melting point, boiling point, solubility )will also change.

用中文解多次畀你聽,鹽,有好多隻,當你係食鹽氯化鈉, 佢係由Na+Cl-組成,

由ionic bond組成結構(molecular STRUCTURE), 因為係好強,所以佢會O係自

然環境中以solid state存在, melting point我記得好似要成2000幾3000度, 但因

為帶charge,好容易同水份子(水份子又係帶charge, H帶+, O帶-) 黐埋,

NA黐O, Cl 黐H, 佢地之間又係ionic bonding,都係好穩定既所以Na+Cl-由

cubic molecular structure分解做番ions,離子,所以你會見到鹽溶o係水,但加熱

之後,水份子蒸氣走,但因為本質無變,區區一百度唔可以boil到鹽,佢又變番做

固體! 要改變佢既chemical properties既話呢,就要幫Na+同Cl-分手,再搵過另一

個partner畀佢,情況好似電解咁,幫佢地回復單身,咁佢地既chemical property就

會改變,呢個又關係到氧化還原既問題啦

2009-10-20 03:54:57 補充：
nonono,如果話係一個chemical reaction, 就要係要換左個partner先, o係NaCl呢個溶o係水既情況黎睇,佢無換過任何一個partner,仍然都係得NaCl,水仍然都係水份子,

但有d情況會唔同,例如將一粒鈉放入水,佢好似溶左咁,但實際呢,就產生左化學作用,變左氫同埋NaOH出黎,搶走左水入面OH果PART,你蒸走晒D水,你唔會再可以攞番粒鈉出黎,你一定要經過電解先可以做得番粒鈉,過程需要能量,因為鈉同水既Chemical reaction中釋放左熱能出黎,o係物理化學角度,你要抵償番之前既能量釋放先可以重新返回(reduction)當初既matter!

2009-10-20 03:55:03 補充：
你提到果個example, 我諗係solution mixture黎既copper ion黐落其他anion樹,會form一d新既野o係杯溶液入面,話係chemical reaction. 但當copper ion遇到一個比chloride畀鐘意既對象(穩定),佢會放棄chloride,跟住會同另一粒anion黐住,跟住會結婚添(form到一個新compound but insoluble),o係呢樹至緊要係要form insoluble呀,form既過程會發熱,新出黎既會無晒之前copper chloride既特性

2009-10-20 04:00:35 補充：
如果無其他ionic compound既copper II chloride既solution,你話form番粒copper II chloride,咪即係加熱蒸走d水or不斷咁加copper II chloride落d solution樹令佢saturated,再冷卻,呢個叫crystallization呀,又係physical proportery黎咋嗎,所以你睇清楚佢上文有無其他野,有既話兩隻solution溝埋先叫mixture呀,單一隻溶o係水叫solution,記住,係溶o係"水",呢樹水只係solvent,唔係reagent!!!!!

2009-10-20 04:11:03 補充：
同埋攪清楚,ionic bond既特性係用黎解釋chemical property同physical property架,chemical property就係佢地高穩定性,唔易還原,需要其他reducing agent去幫佢地,又或者要進行replacement(都係去搶人地個partner)!
而佢既physical property係高水溶性(會有例外,有d唔溶,呢個關乎原子配對同佢地點樣pack個solid state呀), 高melting point, 高boiling point(呢個超高,煮溶既鹽可以導電,蒸唔走因為ionic bond超強),明無?

2009-10-20 04:14:43 補充：
買個機會賺你廾分超辛苦~

我用中文答你啦

鹽(最常見有NaCl)加入水之後...通常都係溶解
溶解係一個物理改變....因為佢由固體轉成溶液..但其中冇任何化學變化
即鹽本身仲係擁有佢ge化學性質...冇任何化學改變.....只係外在改變

boiling point
melting point
density
solubility

等等都係physical properties

it will result in physical properties
the water will change salty
it won't have produce a new thing

You mean, physical or chemical changes?
It only result in physical change.