本區搜索:
Yahoo!字典
打印

[Phy] AL PHY 2001 Q10 part cii Gases

[隱藏]

AL PHY 2001 Q10 part cii Gases

10. Two containers A and B with volumes 100 cm3and 500 cm3 respectively are connected by a tube of negligiblevolume as shown in Figure 10.1.  The tap T for controlling gas flowis closed initially.  Container A contains an ideal gas ata pressure of 12 ´ 105 Pa while there is a vacuumin container B.  The temperature of the twocontainers is maintained at 0°Cby two separate water baths with melting ice.


        (a)    Calculate the number of moles of gas incontainer A.


           Ans : 0.0529 mol





      (c)  The water bath for container A is heated until the water boils. The tap T remains open.  Calculate


            (i)    the equilibrium pressure of the gas in thetwo containers;


          Ans : 2.09 x 10 ^5 Pa


            (ii)   the net amount of gas, in moles, that passedthrough the connecting tube during the heating process.


            我既做法:

                 pV = nRT
                (2.09 X10 ^5)(100*10^(-6)) = n (8.31)(100+273)
                                                     n= 0.00684 mol

                So, the net amount of gas , in moles , that passed through the tube :

                0.0529 - 0.00684  = 0.04606 mol

                但 marking 就

                So, the net amount of gas , in moles , that passed through the tube :
                 
                (0.0529 / 6) - 0.00684  = 0.04606 mol


點解要除6既????
唔該
   

TOP

Please note that before A is heated, the gas has reached a steady equilibrium
-->gas is evenly distributed in A and B
-->the number of moles of gas in A is only 0.0529/6 mol, instead of 0.0529 mol
that is why 0.0529 is divided by 6 before eliminating 0.00684

I hope this may give a help.

TOP

引用:
原帖由 Pockhin 於 2016-7-23 05:02 PM 發表
Please note that before A is heated, the gas has reached a steady equilibrium
-->gas is evenly distributed in A and B
-->the number of moles of gas in A is only 0.0529/6 mol, instead of 0.0529 mol
...
Thank you 先.

但我都係唔太明除6係點來?

TOP

引用:
原帖由 winghang4 於 2016-7-23 05:10 PM 發表


Thank you 先.

但我都係唔太明除6係點來?
I forget to explain the origin of 6
Actually 0.0529/6 is the number of moles of gas in A

In part (a) and (b), the number of moles of gas in A is not yet calculated
As the gas in A and B are of the same temperature and pressure
number of moles of gas is directly proportional to the volume
as volume of A: volume of B is 1:5
-->number of moles of gas in A: B is also 1:5
That's why the number of moles of gas in A is 0.0529/(1+5) mol
6科5**
http://lsforum.net/board/viewthread.php?tid=273337

TOP

引用:
原帖由 Pockhin 於 2016-7-23 05:19 PM 發表

I forget to explain the origin of 6
Actually 0.0529/6 is the number of moles of gas in A

In part (a) and (b), the number of moles of gas in A is not yet calculated
As the gas in A and B are of  ...
我明啦....

唔該你既詳盡解答

TOP

重要聲明:小卒資訊論壇 是一個公開的學術交流及分享平台。 論壇內所有檔案及內容 都只可作學術交流之用,絕不能用商業用途。 所有會員均須對自己所發表的言論而引起的法律責任負責(包括上傳檔案或連結), 本壇並不擔保該等資料之準確性及可靠性,且概不會就因有關資料之任何不確或遺漏而引致之任何損失或 損害承擔任何責任(不論是否與侵權行為、訂立契約或其他方面有關 ) 。