延伸題：
如果題目問點解唔可以用acidified AgNO3
是否Ag2Cr2O7 會soluble in HNO3 such that no observance first appearance of Ag2Cr2O7?
?????
其實用standard acidified AgNO3 ok ?
yes
我主要問Ag2Cr2O7唔會soluble in HNO3嗎？
因為我見話大部份salt soluble in HNO3..
[DSE化學2017]同學準備好DSE CHEM未?
化學艾維斯
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我主要問Ag2Cr2O7唔會soluble in HNO3嗎？
因為我見話大部份salt soluble in HNO3..
想問點解3(a)(iii) 答案係column chromatography？
因為tlc只係話比你知果3隻substance個高低位
真係要extract返隻野出黎要用column
延伸題：
如果題目問點解唔可以用acidified AgNO3
是否Ag2Cr2O7 會soluble in HNO3 such that no observance first appearance of Ag2Cr2O7?
?????
其實用standard acidified AgNO3 ok ?
yes
我主要問Ag2Cr2O7唔會soluble in HNO3嗎？
因為我見話大部份salt soluble in HNO3..
好似唔soluble
想問點解3(a)(iii) 答案係column chromatography？
因為tlc只係話比你知果3隻substance個高低位
真係要extract返隻野出黎要用column
想問呢，TLC話我地只substance polarity difference
之後有column, 會否有機會同時沖曬所有substance落黎？
如果會，點知同點避免？
想問點解3(a)(iii) 答案係column chromatography？
因為tlc只係話比你知果3隻substance個高低位
真係要extract返隻野出黎要用column
想問呢，TLC話我地只substance polarity difference
之後有column, 會否有機會同時沖曬所有substance落黎？
如果會，點知同點避免？
Like this case spot A and B
Spot A adhere more strongly in stationary phase
-> stronger intermolecular attraction with stationary phase
-> 理論上In column 會行得慢過spot B
Toxic 同poisonous 有冇分別
延伸題：
如果題目問點解唔可以用acidified AgNO3
是否Ag2Cr2O7 會soluble in HNO3 such that no observance first appearance of Ag2Cr2O7?
?????
其實用standard acidified AgNO3 ok ?
yes
我主要問Ag2Cr2O7唔會soluble in HNO3嗎？
因為我見話大部份salt soluble in HNO3..
係所有NO3- (nitrate) salt 都soluble in water 嘛？
延伸題：
如果題目問點解唔可以用acidified AgNO3
是否Ag2Cr2O7 會soluble in HNO3 such that no observance first appearance of Ag2Cr2O7?
?????
其實用standard acidified AgNO3 ok ?
yes
我主要問Ag2Cr2O7唔會soluble in HNO3嗎？
因為我見話大部份salt soluble in HNO3..
係所有NO3- (nitrate) salt 都soluble in water 嘛？
No ah
Like Ag2SO4 it is soluble in HNO3...
延伸題：
如果題目問點解唔可以用acidified AgNO3
是否Ag2Cr2O7 會soluble in HNO3 such that no observance first appearance of Ag2Cr2O7?
?????
其實用standard acidified AgNO3 ok ?
yes
我主要問Ag2Cr2O7唔會soluble in HNO3嗎？
因為我見話大部份salt soluble in HNO3..
係所有NO3- (nitrate) salt 都soluble in water 嘛？
No ah
Like Ag2SO4 it is soluble in HNO3...
注意 Mohr method個product係Ag2CrO4唔係Ag2Cr2O7
From wiki:
The solution needs to be near neutral, because silver hydroxide forms at high pH, while the chromate forms H2CrO4 at low pH, reducing the concentration of chromate ions, and delaying the formation of the precipitate. Carbonates and phosphates precipitate with silver, and need to be absent to prevent inaccurate results.
就算假設你assume soluble in HNO3
你加acidified AgNO3 into a sample
個acidity即刻 dilute晒
所以你話soluble in HNO3哩個原因唔成立
咩都未溫想攞2可以點溫.....
學校預我1
學校預我1
?????
其實用standard acidified AgNO3 ok ?
yes
我主要問Ag2Cr2O7唔會soluble in HNO3嗎？
因為我見話大部份salt soluble in HNO3..
係所有NO3- (nitrate) salt 都soluble in water 嘛？
No ah
Like Ag2SO4 it is soluble in HNO3...
注意 Mohr method個product係Ag2CrO4唔係Ag2Cr2O7
From wiki:
The solution needs to be near neutral, because silver hydroxide forms at high pH, while the chromate forms H2CrO4 at low pH, reducing the concentration of chromate ions, and delaying the formation of the precipitate. Carbonates and phosphates precipitate with silver, and need to be absent to prevent inaccurate results.
就算假設你assume soluble in HNO3
你加acidified AgNO3 into a sample
個acidity即刻 dilute晒
所以你話soluble in HNO3哩個原因唔成立
U r right ...
Thanks for clearing concept
MnO4- + C2O42- 比一般redox相對慢 at first 原因在於- - repulsion
咁是否- - repulsion ge rxn
OCl- + 2I- -> Cl- + I2 呢類都係慢rxn?
咁是否- - repulsion ge rxn
OCl- + 2I- -> Cl- + I2 呢類都係慢rxn?
想問下 preparation of ps hdpe ldpe perspex 洗唔洗識？
想問下 preparation of ps hdpe ldpe perspex 洗唔洗識？
Long form is?
完全唔識
我唔明chromatography係做緊咩
（因）colision of reactant molecule in gas phase is rare
（果）activation energy of reaction is high
咁係咪錯concept？
（果）activation energy of reaction is high
咁係咪錯concept？
點樣分polar同non polar?
點樣分polar同non polar?
睇net polarity in resultant arrow
類似phy resultant force gum
想問下 preparation of ps hdpe ldpe perspex 洗唔洗識？
Long form is?
完全唔識
Polystyrene polyethene ziegler natta 嗰d
（因）colision of reactant molecule in gas phase is rare
（果）activation energy of reaction is high
咁係咪錯concept？
Rare collision -> relatively low T
Not easily to start off a rxn -> Ea high
所以, low T or Ea high is one of the reason
但唔係一定既關係..小心小心
想問下 preparation of ps hdpe ldpe perspex 洗唔洗識？
Long form is?
完全唔識
Polystyrene polyethene ziegler natta 嗰d
ziegler natta應該知個名同係application of free radical substitution is ok
Preparation 應該就
其實我連preparation of nylon 洗咪知都唔肯定
（因）colision of reactant molecule in gas phase is rare
（果）activation energy of reaction is high
咁係咪錯concept？
Rare collision -> relatively low T
Not easily to start off a rxn -> Ea high
所以, low T or Ea high is one of the reason
但唔係一定既關係..小心小心
睇番coordinate of maxwell and energy profile
兩者其實未必有直接關係
想問係可唔可以就咁寫2,4NTP