[DSE化學2019]同學準備好DSE CHEM未? (2)

唔洗

其實得 打atom都得 但技術唔一樣

想問有啲畫圖唔sure想用鉛筆寫
Scan出黎其實睇唔睇到 好驚會睇唔清楚

圖係鉛筆畫 到時畫清楚d

但係唔係 Cu 加 conc H2SO4 會出CuSO4？
同埋其實我地駛唔駛記Cl- 同 Br2 唔會有reaction li d關ecs實際位置嘅嘢？

同埋有邊d setup 係一定要close system 又有邊d 係一定open system

yes 但咁係指其中有部分SO42- not involve reaction

all heating set-up基本一定open
closed system你要measure V / P果d咪要

想問吓 CaCl2 點解可以用黎remove I reacted alcohol🤔🤔😵

呢個唔洗識架wor

parent peak, base peak of mass spec 係咩意思呀

阿Sir 你係條片度mention嘅polarity同Rf value嘅關係係點？越polar嘅話會越soluble係stationery or mobile phase？？？

想問下bromine test, 攪唔清幾時用bromine water 幾時用 bromine in CCl4 or other organic solvent 定其實一樣，用邊隻 check presence of cc double bond, 或者 reducing agent 都得
重有 2012 past paper 問why neon lower boiling point lower than oxygen 一定要答 larger molecular size 唔比答 larger molecular mass, 係咪所有答boiling point 或者 melting point 用molecular size 答就無死，唔好用molecular mass

重有d past paper ms 用ecs position 解釋, 例如解釋metal A has lower ECS position than metal B, 所以metal C remains as negative electrode of the chemical cell, 個marking scheme 無寫 reducing power, 我習慣用reducing power 答得唔得，話 metal A has lower reducing power than metal B, 2012 paper 1 3d

麻煩阿sir, 我今日睇返d past paper 應該好多問題

雖然唔係好重要
但係想問下佢syllabus咁寫 thiosulphate加acid 同 iodine clock之外既clock expt有冇機會考
例如methanal clock expt個啲

想問下liquid liquid extraction 個到最後攞到個個product洗唔洗wash and dry ?
好似2016 q3c(ii)個到咁

想問each water molecule can form two intermolecular hydrogen bonds with other water molecules, 咁 hf molecule 同 nh3 molecule can form 幾多個hydrogen bond 呀 由其係nh3 我知佢lone pair 同有3 h atom 可以form hydrogen bonds 但得一個lone pair，我唔知係咪咁當只可以form 1 個 intermolecular hydrogen bond

enthalpy change of decomposition 係咪out 左 c?

如果hcl 轉h2SO4, 個reaction rate 會 increase，係咪唔可以寫double 呀

做liquid liquid extraction 最後一步個陣幾時先要recrystallise舊想要嘅野？

各位聽日考chem既加油

For an equilibrium system with all the reactants and products in gaseous state, while decreasing the volume/increasing the pressure,will the concentration of both reactants and products increase? So if that's he case, will both the forward and backward eaction rate increase?

本身都冇in過syl
但你都要識計個enthalpy change