本區搜索:
Yahoo!字典
打印

[Chem] ch28 simple chemical cells 一問

[隱藏]

ch28 simple chemical cells 一問

我不太明白(c)和(e)

(c)Why the two metal strips in potato A should be interchanged in order to increase the multimeter reading?

(e)why will the multimeter drop to 0 V?

求高人解答
thanks
附件: 您所在的用戶組無法下載或查看附件
   

TOP

firstly, the multimeter actually measures the voltage in this question
and this voltage will increase with the increase in the difference between tendencies for the two metals to form ions (i.e. for the metals to lose electrons)

Therefore, I think u may interpret the question in the following way

So, in Potato A, if the copper and zinc strips are interchanged, the electrons flow from magnesium to copper (instead of from Mg to Zn, which is the original set-up), as copper lose electrons to form ions less readily than zinc. Therefore, the difference between tendencies to form ions is larger, and hence a greater voltage can be produced, thus increasing the multimeter reading.

And for question (e), if the Zn strip is replaced  by a Mg strip, there will be no voltage produced as the difference in tendencies for the 2 Mg strips is simply zero. So, the multimeter reading will drop to 0 V.

So, just remember 'voltage will increase with the increase in the difference between tendencies for the two metals to form ions', then I think u can handle this kind of questions well: )

Gayau

TOP

thank you!!  

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 ) 。