北京时时彩每天开奖号码

您好,歡迎訪問新航道官網SAT頻道!

在線咨詢

SAT(美國高考)

SAT香港考試團啟航夢想

2019新航道秋季班,免費領取價值688元精品課程!

您當前的位置 ? 新航道官網 ? SAT ? SAT化學 ? 文章正文

SAT化學練習:Limiting Reagents

2013-04-02 00:00     供稿單位: 互聯網    

出國英語考試有哪些 雅思6.5是什么水平 雅思閱讀評分標準 托福閱讀評分標準 雅思和托福的區別

 

    今天新航道SAT頻道小編為大家整理了SAT化學練習:Limiting Reagents,供大家參考,以下是詳細內容。

  Have you ever noticed that hot dogs are sold in packages of 10, while the buns come in packages of eight? In this scenario, the buns are the limiting reactant in the sense that they limit the hot dog preparation to eight. The limiting reactant or reagent is the one that is consumed first in the chemical reaction, and its consumption halts the progress of the forward reaction.  When answering questions about limiting reagents on the exam, your first step should always be to convert all the masses you were given into moles. You should set up your table as you did before, only now you’ll have two amounts and thus two numbers of moles to get you started.   Let’s look at a specific question, involving the Haber process. Basically, this is the process of making ammonia from the reaction of nitrogen and hydrogen gases. The reaction is shown below:Molar mass(28.02)(2.02)(17.04)

  Balanced equation N2 +3H2 2NH3

  No. of moles

  Amount

  Suppose you have a total of 25.0 kg of nitrogen to react with a total of 5.00 kg of hydrogen. What mass of ammonia can be produced? Which reactant is the limiting reactant? What is the mass of the reactant that’s in excess? Insert the masses in the correct rows and find the number of moles of both.

  Molar mass(28.02)(2.02)(17.04)

  Balanced equation N2 +3H2 2NH3

  No. of moles892 mol2475 mol

  Amount25,000 g5000 g

  Start with nitrogen. You have 892 moles of it available, and in order for the nitrogen to react completely with hydrogen, you’d need 3(892 mol) = 2676 moles of hydrogen, which you don’t have. Therefore, hydrogen is the limiting reagent. Now let’s answer the other parts of the question. The mass of ammonia that can be produced is limited by the amount of hydrogen, so do your calculations based on the number of moles of hydrogen available. Your chart should look like the one below:Molar mass(14.02)(2.02)(17.04)

  Balanced equationN2 +3H2 2NH3

  No. of moles825 mol used2475 mol usedtherefore 1650 mol produced

  Amount 892 mol 23,117 g used 25,000g 5000 g1650 mol (17.04) = 28,116 g produced

 

 以上是新航道SAT頻道小編為大家整理的SAT化學練習:Limiting Reagents,希望對大家有幫助,更多資訊、資料請訪問新航道SAT頻道http://www.mehkj.com.cn/sat/

分享到:
新航道,英語成功之道。第一時間獲取新航道英語學習資料和新鮮資訊,請在微信公眾賬號中搜索「新航道英語」或者「xhdenglish」,或用手機掃描左方二維碼,即可獲得新航道每日精華內容推送和最新英語學習經驗分享,并參與新航道舉辦的各項活動。
責編:新航道小編
北京时时彩每天开奖号码