? asked in 科學化學 · 1 decade ago

Experimental quesions?化學高手幫幫忙

Ok..there are no \"correct\" answers!!...just discuss your thoughts, plans and ideas..to written up laboratory reports. One page for each experiment.

1. You are given a piece of sponge . Task: What percentage of the sponge is air space?

2. You are given five colourless solutions A,B,C,D and E. One is a 0.1 M hydrochloric acid solution, one is a 0.1 M sodium hydroxide solution, one is a 0.1 M sodium carbonate solution, one is a phenolphthalein solution and one is water. Task: Without using any other reagents, identity the five solutions. Express the logic of your conclustions clearly.

第一個問題,請說明一下實驗時使用的方法...還有理論之類的....

第二個問題,請說明一下為什麼會有一些反應的產生...是如何分類那些溶液的???

希望有人能幫我解答一下喔!!!!我一點概念都沒有.....Thank you so muck.........

1 Answer

Rating
  • 1 decade ago
    Best Answer

    第一問

    1.將海綿烘乾,以天平秤其質量並紀錄為Mo (g),並計算海綿體積,紀錄為Vo (cm^3)

    2.讓海綿完全浸入水中,並在水中擠壓至完全沒有氣泡

    3.將吸滿水的海綿放到天平上測量質量並紀錄為Mf (g)

    4.將(Mf-Mo)/D,算出水的體積Vw (D為水的密度,一般用1.0(g/cm^3))

    5.水的體積即為海綿內部空氣的體積,即Vw = Vair,再用Vair/Vo

    即得到空氣所佔百分比

    第二問

    1.首先將五種溶液分別以手搧聞氣味,若有刺鼻酸味者,則可判定其為鹽酸溶液

    2.將剩下四種溶液各取適量體積,與等量鹽酸個別混和

    3.混和後產生氣泡者,則可判定其為碳酸鈉溶液

    Na2CO3(aq)+HCl(aq)NaCl+CO2(gas)+H2O

    4.將剩下三種溶液取適量,與等量鹽酸混和,待混和溶液完全蒸發後,若留有白色結晶者,則可判定其為氫氧化鈉溶液

    NaOH(aq)+HCl(aq)NaCl+H2O ,NaCl(aq)+H2ONaCl(solid)

    5.將剩下的兩種溶液取適量,與等量氫氧化鈉溶液混和,若變色為粉紅色者,則可判定其為酚酞溶液

    6.最後剩下的,即為水

    hydrochloric acid solution:鹽酸溶液

    sodium hydroxide solution:氫氧化鈉溶液

    sodium carbonate solution:碳酸鈉溶液

    phenolphthalein solution:酚酞溶液

    water.水

    2006-03-12 14:50:54 補充:

    方程式的箭號無法顯示,修正如下:Na2CO3(aq)+HCl(aq)---->NaCl+CO2(gas)+H2ONaOH(aq)+HCl(aq)---->NaCl+H2O NaCl(aq)+H2O---->NaCl(crystal)

    2006-03-12 18:24:04 補充:

    歡迎,只要是我懂的知識,絕對不吝與大家切磋分享,我也希望能在各位身上學到寶貴的知識!!

    Source(s): 本身理化知識
Still have questions? Get your answers by asking now.