chem 問題.....

維記．鮮奶

點解limestone solube in sulphuric acid 呢句野唔岩？ 要係dissolve？
同埋limestone係咪唔會decompose on heating？
CuO + NaOH 會唔會出PPT？
電解CuSO4,cathode用Cu,點解話cathode附近既H+ conc. 高左唔岩？
點解glucose 會係strong electrolyte？

thx.....

meow喵

CaSO4好似係in-soluble-_-

Zend

邊個話GLUCOSE 係STRONG electrolyte =.=

維記．鮮奶

邊個話GLUCOSE 係STRONG electrolyte =.=
Zend 發表於 28-4-2009 23:42

請問點分weak 同埋 strong ？

Zend

conductivity...,其實都係比較

但glucose 基本上唔算係electrolyte...(with exception, no need to care)
佢唔會被電流分解到, by definition, not an electrolyte (in aq/ molten state, can conduct electricity + can be decomposed upon current )

維記．鮮奶

conductivity...,其實都係比較

但glucose 基本上唔算係electrolyte...(with exception, no need to care)
佢唔會被電流分解到, by definition, not an electrolyte (in aq/ molten state, can conduct electricity  ...
Zend 發表於 29-4-2009 00:09

錦如果我拎隻CH3COOH泥同佢比,濃度一樣,
邊隻conduct得好d？

Zend

錦如果我拎隻CH3COOH泥同佢比,濃度一樣,
邊隻conduct得好d？
維記．鮮奶 發表於 29-4-2009 00:13

根本glucose solution都唔導電...(你用一千萬V 直流電就可能例外)
CH3COOH solution導到

維記．鮮奶

根本glucose solution都唔導電...(你用一千萬V 直流電就可能例外)
CH3COOH solution導到
Zend 發表於 29-4-2009 00:19

說到底,即是個exception 吧？
那其他呢- -？

Zend

1, 比人答左
2, 書有吧
3, 這個不會問吧,而且你都溶唔到CuO.
而且應該唔會變野, 因為佢唔係amphoteric
4,  電解BRINE 果時有係因為有用到附近水的ION, 而令果REGION 變左acidic/basic...
而電解CuSO4(aq), using Cu as cathode...

維記．鮮奶

1, 比人答左
2, 書有吧
3, 這個不會問吧,而且你都溶唔到CuO.
而且應該唔會變野, 因為佢唔係amphoteric
4,  電解BRINE 果時有係因為有用到附近水的ION, 而令果REGION 變左acidic/basic...
而電解CuSO4(aq), using Cu ...
Zend 發表於 29-4-2009 00:31

大致都想起來了,明明是學過的東西-.-
都忘了(汗

這樣說的話,在cathode留下的應該是SO4 2-,
那anode就會增加H+ 的conc.了？