上幾個星期化學友同幾個學生去左香島中學睇一年一度嘅化學奧林匹克(Chemistry Olympiad)比實,除左去學吓o野同埋觀摩吓各隊表現之外,順便都見o下d幾個月冇見嘅老友。
今年嘅主題係chemistry in commercial products。決賽Present嘅六組同學都搵咗d唔同嘅commercial products去分析同研究: 螢光棒、染髮劑、洗衣液、解酒藥、螺旋藻片同埋驅鳥劑。
講真,六組同學嘅表現幾出色,見到佢哋都花咗唔少心機去準備,係一場高質素嘅比賽。化學友唔想o向e度慢慢講d關於o個日化學嘅內容,反而化學友想講講o個日嘅冠軍St. Paul’s Convent School。其實o個日未宣報邊個係冠軍,化學友都100%肯定St Paul會得到champion o架啦。佢地o個日嘅表現可以話接近完美,勝出係實至名歸。如果同學仔有參加o個以前d chemistry或者science嘅competitions,都會知道St Paul係常客,而每次佢地都會有好好嘅表現。一次成功仲可以話係luck,但每次都有高水準表現就一定係有佢地成功之處。化學友發覺最明顯St Paul比其他學校好嘅地方係佢地每次比賽都可以做到”以終為始”,而一般學校好多時都做唔到。同學仔可能會問乜o野叫做"以終為始" ? 簡單o黎講就係每決定做一件事時,第一樣o野要做就係要定下明確目標先,然後所有過程都係向住e o個目標出發。用St Paul為例,佢地o個project係compare染髮劑,而佢地做嘅每一個experiment或者investigation都係有明確咁為左compare染髮劑而做,唔會左右搖擺。反觀其他學校或多或少都有d守唔住目標,佢地好多時都係為左做實驗而做實驗,而o個d實驗同佢地嘅target係冇乜關係,當d judge問佢地為乜做e o個實驗,同常佢地都唔係好知點解。就係因為有e o個分別,好多時St Paul參加competition都會欏到好成績。老土d咁講,每個人成功都一定有佢嘅優勝地方,絕非僥幸o架。化學友希望同學仔以後參加任可science competition都一定要記住”以終為始”,咁樣你地得到好成績嘅機會就大好多o架啦。(P.S. 同學仔唔好以為化學友o向到同St. Paul賣告白,化學友同St. Paul一d關係都冇o架,只不過化學友真係幾欣賞佢地嘅表現,覺得同學仔參加competition時可向佢地借鏡咋。)
有興趣睇吓Chemistry Olympiad嘅同學仔,可以去e個website睇睇丫:
http://www.hkasme.org 搵 ”HKChO-12th”
16 則留言:
化學友:
雖然都考完,不過都有chem 問題...
1.點解soapless detergent有branch就會non-biodegradable?
2.點解metal+dilute HNO3 出NO先?直出NO2唔得嫁?
---------------------------------
3.你覺得邊本AL書最正?
1. 請問寫essay 洗唔洗寫 equation ??
化學友:
1. 寫essay 係唔洗寫 equation,因為essay係考communication skill (傳意技能),以文字表達chemical knowledge。除非係題目要求,平日係唔使寫equation嘅,仲要記住唔好以point form寫出,真係會扣分o架。
請問化學友,
如果essay唔洗寫equation,咁舊年06年果份咪要寫4個similiarity?
唔係2個similarity+2個equation咁比分咩?
化學友:
可否解釋2007CE CHEM MC
Q2?
Q18 KOH唔係ionic compound,但係都soluble & conducting?
Q31?
Q40?
Q42?呢兩隻compound會eliminate 咩small molecule?
Hello~化學友...
第一次上黎問你野...
好多呀sir都話08年既chemistry會好難
咁你又覺得點呢??^^
因為我係08年會考生...
所以都幾擔心呢個問題
thx
你好呀
我想係d岩岩考完會考d個假自修一下AL chem,我應該點入手?例如可以借咩書睇?
HI 化學友
近日我就學緊 chlorine 呢個topic.
裡面提及chlorine water & chlorine bleach
甘其實chlorine water 可吳可以用在漂白方面呢 ? 因為佢react with water, form
OCL- ?雖然我知chlorine water 系acidic
甘系味因為甘,佢就吳可以用來作漂白用呢?
化學友,我想問呢mecury cathod係咪out左c架?
化學友你好~
係關於al chem 的
1.
係weak acid dissociation入面
increase volume of water
會唔會increase degree of dissociation at fixed tempature?
if yes ,why?
2.
increase volume of water會唔會
increase 個solubility?
化學友:
點解先用conc sulphuric acid 然後再加water 去整 alcohol 會好過直接用dilute sulphuric acid for hydrolysis?
感謝
想問個唔關於化學既問題
我見到你個blog同第2個好相似
但係佢係econ友
http://www.friendonomics.blogspot.com/
我想知你地識唔識得對方架???
咁仲有冇其他友???
e.g. physics友,bio友,cit友,中文友,eng友,amaths友......
SO4 2−(aq) + 4H+ + Cu(s) → Cu2+(aq) + 2H2O(l) + SO2(aq)
Ar Sir,
呢條 Equation 係唔係 break 左 Redox 的Rule?
咁點解呢個 Reaction 都得 gei?
THX
老師,我想問問在electrolysis 裏用dilute sodium chloride 所得的product 是否和concentrated 的相同(chlorine 和 hydrogen)?我校老師這樣的分:very dilute, dilute, concentrated where dilute=concentrated。
至於lauw 提出的equation,我看是沒有break redox law 的,copper 由0 去+2,sulphur 由 +6 去+4
我有d electroysis ge野有d唔明呀!!
which of the following substances will be decomposed if they are added to the distilled water in the electrolysis?
(1) Mercury
(2) Copper(II) chloride
(3) Ethanol
點解 (1) (3)唔得ge???
仲有如果electrolysis用graphite來做electrodes, 係咪會同產生出來ge product oxygen react嫁? 咁係唔係一有oygen產生出來就唔可以用graphite嫁?
致 suzan
關於第一個問題,因為mercury 和 ethanol 都不溶進水,沒有mobile ions 所以不會被elctrolysis decompose 。copper(II) sulphate溶入水後有mobile ions,ions還會polarize H2O,產生H+ 和 OH- ,Cu 和 O2 會形成。
關於第二個問題,graphite 是inert elcetrode ,和elctrolysis 放出的oxygen 是沒有reaction的,可以放心使心。
我有幾條問題想問下:
1) Which bond is the strongest --- ionic bond, covalent bond or metallic bond? Also, which one is the weakest?
2) Can silicon and oxygen join togester to a compound with a simple molecular structure like O=Si=O ?
3) How to distinguish carbonates and hydrogencarbonates?
4) In metal displacement reaction, if I put potassium to displace a solution containing a less reactive metal ions, will potassium react with water to produce hydrogen?
5) In distillation of pure aqueous sodium chloride solution, water can be collected. Could I get sodium chloride from the set-up? Could I use this method to extract sodium chloride from aqueous sodium chloride solution?
好似好多問題咁, 希望你可以解答下我的問題, 唔該曬。
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