化學

我想問下(Cl2)+(2e-)------〉(2Cl-)依一個reaction點解會發生o既???

Cl2唔係已經係一個covanlent bond,已經穩定左咩?
點解仲要吸取electron呢????

咁Cl定Cl2 reactivity o的呢???點解呢????

thx~~~~~~~~~~~~~~~!!

2007-04-06 11:20:08 · 2 個解答 · 發問者 ? 1

本人想問氨溶液和硫酸的中和作用化學式應寫成
OH- + H+ → H2O 還是
2NH3 + H2SO4 → (NH4)SO4 同埋點解

另外,SO32- 加 H+係出SO42- 還是SO2呢？

謝謝大家

2007-04-06 10:40:48 · 2 個解答 · 發問者 fung 3

國內使用不銹鋼常用SUS 304 316，因為其不具磁性而能輕易分辨
但現在有對岸用SUS 201 202來代替SUS304
因為成本優勢過強
（註
SUS 201 NI 3.5%~5.5%
SUS 202 NI 4.0%~6%
SUS 304 NI 8.0%~10%
SUS 316 NI 12%~15%
捉低標來比，202 VS 304 4% VS 8%的含量
而依成本來算，SUS 201 202只要304的一半價)
且開始流竄台灣
但聽說SUS 201 202也是不具磁性，而且電解藥水調配得宜，2字頭的也能電解
最明確的作法當然是做材質分析
但成本高
所以有無簡單的方法來分辨手中的東西是SUS 2XX還是SUS 304 316呢

2007-04-06 09:53:15 · 3 個解答 · 發問者 dylai 1

1). A sodium hydroxide solution has been exposed to air for a long time. When dilute hydrochloric acid is added to it, colorless gas bubbles are given out. Explain the observation with the help of equations.

2). A solution of ammonia has a strong smell of ammonia gas. What does this tell you about the particles present in the solution?




please solve them....thanks a lot

2007-04-06 07:22:29 · 1 個解答 · 發問者 ☆ 天 與 空 ★ ◤ 4

is it true that all bases can react with ammonium compounds to give out ammonia gas on heating?

2007-04-05 18:04:35 · 1 個解答 · 發問者 Silvia 1

點解 CaCO3 係antacid tablet~?? 唔係會放 CO2 搞到胃氣脹ga咩~???

2007-04-05 17:14:39 · 2 個解答 · 發問者 chun yu 1

如題 ..........

2007-04-05 06:32:01 · 1 個解答 · 發問者 Kenneth 2

如題 .............

2007-04-05 06:31:24 · 1 個解答 · 發問者 Kenneth 2

氧化鋁有分成許多成分跟規格 有95% 99% 99.8%
差別在哪呢 那如果要做成較大型的陶瓷用品 會很困難嗎
例如 兩米長 或三米長的大面積 國內有廠商作的出來嗎
請指教 謝謝

2007-04-04 07:34:12 · 1 個解答 · 發問者 nancynonno 1

The equilibrium constant (in terms of partial pressures of gases) of the following reaction is 10atm at 1000k.

C(graphite) + CO2(g) <-----> 2CO(g)

What is the total pressure of an equilibrium system of CO(g), CO2(g) and the graphite containing 6% of CO2 by volume？

2007-04-03 18:58:02 · 1 個解答 · 發問者 David 1

How many possible constitutional isomers of cycloalkane having the molecular formula C5H10?
How many possible constitutional isomers having the molecular formula C6H14?
How many possible constitutional isomers of alkene having the molecular formula C5H10?

2007-04-03 14:26:18 · 2 個解答 · 發問者 教你開智慧 5

Study design
Thirty healthy subjects (14 men and 16 women) between 20
and 39 y of age were recruited. Subjects were asked to abstain
from consuming tea, tea-related products, vitamins, minerals,
and dietary or herbal supplements throughout the study period.
Heavy tea drinkers and users of hormone therapy or antibiotics
were excluded. All subjects were screened with a complete medical
history and signed the informed consent form.Arandomized
33 crossover design with a 1-wk washout period was used for
the intervention study. The subjects were randomly assigned to 3
different sequences of GT, BT, or GTS at the University of
California, Los Angeles (UCLA), General Clinical Research
Center (GCRC).

30 個健康的主題(14個男人和16名婦女) 在20之間
並且年齡的39 y被招募。 主題被要求棄權
從吃完茶，有關茶的產品，維生素，礦物質中，
以及在整個研究時期期間的飲食或者草本植物的補充。
激素治療或者抗菌素的難消化的茶飲者和用戶
被排除。 全部主題被一次完全的體格檢查篩選
歷史和在明智的應允form.Arandomized上簽字
3 _ 有一個1－wk失敗時期的3種交叉的設計被使用為
干涉研究。

2007-04-03 11:27:28 · 1 個解答 · 發問者 sumin 1

Tea preparation
Tea flavanol, theaflavin, and caffeine concentrations were measured
in the tea beverages, which were prepared in the same way as in a previous study that used HPLC analysis (3). For the intervention study, hot BT and GT were prepared by trained staff at theUCLAGCRC. Four bags ofBTor 3 bags ofGTwere added to 426mLboiling water and steeped for 5 min. The number of tea bags was chosen to match the EGCG content. Tea was served immediately with or without sugar or 45 mL milk.

茶準備
茶多酚，theaflavin 和茶鹼集中是 在茶飲料裡測量，在相同裡準備 如同在使用HPLC 分析的一項以前的研究裡的模式 ( 3 ) . 為 干涉研究，訓練的人員準備了熱BT 和GT 在theUCLAGCRC。 4 袋ofBTor 3 袋ofGTwere增加 在426mLboiling 水既沒適合5分使浸濕。 茶的數量 袋被選擇與EGCG 內容相配。 茶被提供 立即有或沒有糖或者45 mL牛奶。

2007-04-02 13:28:37 · 1 個解答 · 發問者 sumin 1

Can SO2 decolorize KMnO4 ???why??

Is chlorine water a mixture? what is the observable change with NaCl ?

2007-04-02 06:41:01 · 1 個解答 · 發問者 chun yu 1

假設依家有兩舊Zn..
第1個重1g
第2個重2g
佢地react with HCl(aq)..
邊個react得快d.?

2007-04-01 17:43:41 · 1 個解答 · 發問者 KanT 3

conc.H2SO4 + NaCl + MnO4 點出 white fume?
conc.H2SO4 + NaBr + MnO4 點出 red fume?
Heat KNO3 出乜
Heat Mg(NO3)2 出乜
唔該寫埋d equation~

2007-04-01 11:07:12 · 2 個解答 · 發問者 Anonymous

1. Explain the meaning of pH, both in terms of hydrogen ions and hydronium ions.

2. Why do chemists not usually use pH to describe [H3O+] when the pH value would be a negative number?

2007-04-01 09:52:30 · 1 個解答 · 發問者 sl_ye 2

簡單的問題 只有固體可以做FLAME TEST嗎 還是液體也可以?

我需要準確的答案 =) 謝謝

2007-04-01 07:37:27 · 2 個解答 · 發問者 ? 2

1. Citric acid is an electrolyte
2. When citric acid is dissolved in water, citric acid molecules become mobile.

When the second statement is not the explanation of the first statement?

2007-04-01 07:14:37 · 2 個解答 · 發問者 Saturday 3

如何減少二氧化氮?

2007-03-31 08:02:09 · 1 個解答 · 發問者 cho ling 3

點樣分開ethanol同thanoic acid???

2007-03-31 07:53:36 · 2 個解答 · 發問者 ? 1

When a substance X is electrolysed using platinum electrodes, a gas is collected at each electrode. X may be
A. silver nitrate solution
B potassium chloride solution
C molten sodium chloride
D molten copper(II) chloride

The answer is B but why not C?

2007-03-31 04:24:43 · 2 個解答 · 發問者 Saturday 3

1993 CE CHEM # 9
Which of the following reactions would produce a halogen?
(1) sodium chloride + conc sulphuric acid
(2) sodium bromide + conc sulphuric acid
(3) sodium iodide + conc sulphuric acid

A (1) only
B (3) only
C (1) and (2) only
D (2) and (3) only

Why the answer is D?

2007-03-31 04:20:31 · 2 個解答 · 發問者 Saturday 3

試就下列各個反應,
i)寫出所有預期觀察的變化
ii)寫出生成物的名稱
iii)寫出涉及反應的完全反應式
iv)寫出涉及反應的離子反應式


(a)稀硫酸與稀氨水
(b)稀氫氧化鉀水溶液與二氧化碳氣體
(c)稀氫氧化鈉水溶液與硫酸銨固體一起加熱
(d)稀硫酸鋁水溶液與過量的稀氫氧化鈉水溶液

請幫我吧!!!

好複習..救命!!!!!

2007-03-30 18:34:07 · 1 個解答 · 發問者 Rebecca 1

sulphuric acid定nitric acid more volatile?

2007-03-30 06:02:02 · 1 個解答 · 發問者 Saturday 3

"calcium react faster with 1M sulphuric acid than 1M hydrochloric acid."
點解依個statement係錯o既?
sulphuric acid唔係dibasic咩..應該h+ o既concentration係高d ga wo

2007-03-29 19:56:52 · 1 個解答 · 發問者 jc 2

Please write the equation and the colour change when Iron(lll)chloride is addedinto the following chemicals:
1.KCNS
2.KNO3
3.C6H60/PhOH
4.CH3COONa
5.Na2S
6.K3Fe(CN)6
7.NaOH

2007-03-29 17:14:45 · 1 個解答 · 發問者 Smart 3

請列出metal oxide 與hydroxide 有邊隻可溶於水 & 顏色
由 K Na Ca Mg Al Zn Fe Pb Cu Ag 為止

例 :
Soluble in water ? Colour
Copper(II) oxide No Black

2007-03-29 14:07:29 · 1 個解答 · 發問者 chu 2

點解用碳酸鹽分辦唔到濃硝酸同濃硫酸??
碳酸鹽同兩隻酸出既鹽都唔同架喎,一個係硫酸鹽,一個係硝酸鹽,咁點解分辦唔到???

2007-03-29 10:55:08 · 1 個解答 · 發問者 STEVIE-G™ 7

I bought a kind of Vitamin Ca-C tablets which I don't know much about it. It can dissolve in water and you will see bubbles coming out from the Vitamin C tablet. Then soon the water will become yellow and taste sour ( which is the Vit C) . I've searched the information about this and I'm still confused. I need a good explaination of the process and better with a equation.

2007-03-28 16:17:08 · 1 個解答 · 發問者 A student 1