[DSE化學2019]同學準備好DSE CHEM未?

add N2O4, forward rate increase, RHS
你係單方面N2O4 increase (Qc drop)
total gas molecule increase係會令total P increase
但呢個factor係同時apply落forward backward

[url]同時apply指pressure increase will increase both forward and backward rate
至於你pressure高左固然係會favor LHS 但始終你add N2O4呢個動作shift RHS個rffect會大d overall都係RHS
唔好諗得太複雜 睇左你做個main change先[/url]

好 唔該
ok 唔加

如果想follow個reaction 嘅rate 但如果出黎個隻gas係H2，即係好似 Mg+HCl->H2+MgCl2 就唔可以用measure the change in mass of the reaction mixture 呢個方法？係因為H2太輕所以走嘅mass好微？

點解唔可以

實際做唔太好 但理論上做得到
亦可以用pressure sensor 會sensitive d

想問下點解ce 2007 47最後cancel左

呢題嚴格黎講唔算出錯 只係比較含糊 我每年上堂都會攞出黎教
佢原意係想考如果要靠compare rate去compare strength of two acid 有d咩factors係需要"準確地相同"
基本上只要兩個acid solution個concentration同basicity相同就可以fair
由於佢講明Mg ribbons are completely covered by acids
即係個reaction只發生於水底Mg metal同acids solution有contact既surface
至於acid solution喺test tube入面既water level其實唔重要 多d少d都唔會影響到水底既reaction 所以唔洗準確 即係用measuring cylinder就ok
但另一方面 佢又比埋same volume呢個選項你 而題目本身無強調要準確地相同 又無講明係must be the same果種 咁答題角度自然可以揀就好多人會揀埋same volume

dimerization dse係咪唔會再掂到
例如ch3cooh dimer molar mass係120.0個啲

唔考啦

點解唔係lighten then darken?

點解唔係lighten then darken?

gas system黎 你加多d一隻colorless gas 唔會令另一隻colored gas既濃度減少
同你加水入一個colored solution唔一樣
不過佢又問得無稜兩可dd既

如果same carbon atom no 嘅alcohol 同 amine 相比，alcohol個b.p.會高過amine? 做練習見到佢話因為O會electronegative 過N ，呢個位唔係幾明

O-H嘅hydrogen bond stronger than N-H
所以alcohol嘅intermolecular force都會相對地stronger
bp就大啲

咁如果攞alcohol 同amide比呢？with same no of carbon atom

應該amide高啲？
-conh2 form到h-bond 同時又有polar既=o
會有polar attraction (dipole-dipole) between molecules?
alcohol就得h-bond

比較MgO Na2O(ionic oxides) m.p.係咪要討論佢地既atom係lattice入面既packing effiency？

yes
不過其實個factor唔係太明顯 而且有其他更重要既factor 例如avg no of Hbond per molecule, steric effect等 所以比較少講呢樣野