化學 (科學) | fedest.com

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電子親和力是什麼？

所謂的”電子親和力”是什麼？請解釋一下，不懂！

2005-10-11 03:51:50 · 2 個解答 · 發問者 Frank 7

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炸藥：為什麼要加鹽？

鹽有什麼特別的作用？為什麼炸藥裡要放鹽？

2005-10-10 17:50:39 · 2 個解答 · 發問者 Anonymous

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鋅粉+入的量不足............

"含水硫酸銅"加熱成為"無水硫酸銅"粉末
再以"水"溶解無水硫酸銅.........
+入"鋅粉"............直到溶液透明
+入6NH2SO4............... 直到容易不在產生氣泡
烘乾過濾出來的沉澱物就可以得到銅

這實驗是定組成定律
我想請問
1. 鋅粉+入的量不足對實驗有什麼影響呢?
2.實驗中+入過量鋅粉該如何處理?怎樣才不致過量?

2005-10-10 17:44:52 · 3 個解答 · 發問者 Dane 1

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請問銀膠一般可以用什麼容易溶解、稀釋？

我的銀膠已經有點乾掉了
變成QQ的跟口香糖一樣
有沒有什麼辦法可讓他變回原樣？

2005-10-10 14:15:49 · 2 個解答 · 發問者耶耶耶！！！ 2

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李必式冷凝管的作用

如題
請用李必式冷凝管的作用是什麼
長的怪怪的，是用來幹麻的

2005-10-10 14:03:39 · 1 個解答 · 發問者 ? 2

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化合物???????????

可以說一些常見的化合物,組成的元素及符號給我嗎???

感謝(－ｖ－)v

2005-10-10 13:21:11 · 3 個解答 · 發問者 ? 1

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黑糖的化學式和結構式?

黑糖的化學式和結構式?
黑糖的化學式和結構式?

2005-10-10 13:01:10 · 2 個解答 · 發問者又木 1

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什麼是三仙丹?

化學式:HgO(s)

普利斯托利在1774年用"三仙丹"發現出氧氣的。

請問三仙丹的名子由來??
在當時民間有何用途嗎??

2005-10-10 10:47:40 · 1 個解答 · 發問者 Anonymous

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求某有機化合物?

某有機化合物6.51毫克完全燃燒後,得20.47毫克的CO2及8.36毫克的H2O.問何者可能為此化合物?
1.C6H14
2.C5H10
3.C6H12O
4.C4H10O4....................................怎麼算?

2005-10-10 09:33:57 · 3 個解答 · 發問者 Anonymous

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氯酸鉀是酸性還是醶性??

氯酸鉀是酸性還是醶性??
請問一下,謝謝

2005-10-10 08:17:04 · 2 個解答 · 發問者 §◎miki阿米仔◎§ 1

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我想要請問一下Frack Condon!

有關於Frack Condon的原理!
希望能夠詳細一點,謝謝唷!

2005-10-09 19:30:44 · 1 個解答 · 發問者 Vic Chang 1

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1. Calculate the percentage error arising in an experiment when 1ml, 5ml, and 10ml pipets are for transfer and each pipet contains 5 drops of water adhering to the inside of the barrel. A single drop of water has an approximate volume of 0.05ml.

2. If a 0.5ml air bubble is present in the tip of a buret, what percent error in 10ml, 20ml, and 40ml samples will result if air bubble is dislodged during the dispensing of the samples?

謝謝各位大大！

2005-10-09 13:05:16 · 1 個解答 · 發問者怡螢 2

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有關原子、分子與離子

請問；下面這3題的核符號怎麼寫??
1.較Na-21多一個中子的Na-21的同位素；與Na-21，互為同重核且其原子序等於10；有一含有11質子及12中子的核，他是Na-21的同位素嗎?
碳酸鐵，疊氮化鈉，硫酸鈣，硫化銅，氧化鉛。這些化合物的化學式怎麼寫?
因為星期2就要交了....請各位幫幫忙!!

2005-10-09 12:43:09 · 2 個解答 · 發問者 Tako 1

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理化作業= =...

麻煩一下...何位同位素、同素異形體、同份異構物

2005-10-09 08:58:34 · 3 個解答 · 發問者 ? 1

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原文化學的題目!!徵求會翻譯跟解答..謝謝

可以幫忙翻成中文跟幫忙解答ㄇ??感謝

1.Identify the following as either elements or compounds.Refer to the list of elements inside the front cover if necessary.
A.carbon monoxide B.hydrogen C.iron D.titanium E.potash F.sodium bicarbonate

2.Identify the following as either elements or compounds.Refer to the list of elements inside the front cover if necessary.
A.ammonia B.hydrogen C.aspirin D.mercury E.stannous fluoride F.uranium

3.identify the following as either a physical or a chemical property
A.Diamond is one of the hardest known substances.
B.Carbon monoxide is a poisonous gas.
C.soap is slippery.
D.Silver tarnishes.
E.Gold does not rust.
F.Carbon dioxide Freezes at -78C.
G.Tin is a shiny,gray metal.
H.Sulfur burns is air.
I.Aluminu has alow density.

4.identify the following as either a physical or a chemical property
A.Sodium burns in the presence of chlorine gas
B.Mercury is a liquid at room temperature
C.Water boils at 100C at average sea-level pressure
D.Limestone gives off carbon dioxide when heated
E.Hydrogen sulfide has a pungent odor

5.identify the following as a physical or a chemical change
A.the frying of an egg
B.the vaporization of dry ice
C.the boiling of eater
D.the burning of gasline
E.the breaking of glass

6.A handful of sand a mass of 208 g and displaces a volume of 80.0 mL~what is its density?

7.A 125-g quantity of iron has as volume of 15.8 mL~what is its density?