章节大纲

  • Chemical manufacturing plant in a snowy landscape, focusing on process improvement and material production.

    How can we get more product?
    ::我们怎样才能获得更多的产品?

    Chemical manufacturing plants are always seeking to improve their processes.  One of the ways this improvement comes about is through measuring the amount of material produced in a reaction.  By knowing how much is made, the scientists and engineers can try different ways of getting more product at less cost.
    ::化学制造厂总是在寻求改进它们的工艺过程。 改进的方法之一是测量反应中生产的材料数量。 科学家和工程师通过了解生产了多少,可以尝试不同的方式以更低的成本获取更多的产品。

    Conversions Between Moles and Mass
    ::摩尔和质量之间的转换

    The of any substance is the mass in grams of one mole of representative particles of that substance.  The representative particles can be atoms, molecules, or formula units of .  This relationship is frequently used in the laboratory.  Suppose that for a certain you need 3.00 moles of calcium chloride (CaCl 2 ).  Since calcium chloride is a solid, it would be convenient to use a balance to measure the mass that is needed.  The molar mass of CaCl 2 is 110.98 g/mol.  The conversion factor that can be used is then based on the equality that 1 mol = 110.98 g CaCl 2 .  will allow you to calculate the mass of CaCl 2 that you should measure.
    ::任何物质都是该物质具有代表性的微粒的克数。 具有代表性的粒子可以是原子、 分子或公式单位 。 这种关系经常在实验室中使用。 假设对于某个特定物质来说, 您需要3. 00 摩尔的氯化钙( CaCl2) 。 由于氯化钙是固体, 使用平衡来衡量所需的质量是方便的。 CaCl2 的摩尔质量为110.98克/ 摩尔。 那么, 可以使用的转换系数是基于 1 mol = 110.98 g CaCl2 的等值, 您可以计算您应该测量的 CaCl2 质量 。

    3.00   mol   CaCl 2 × 110.98   g   CaCl 2 1   mol   CaCl 2 = 333   g   CaCl 2

    ::3.00摩尔 CACl2x110.98克 CACl21摩尔 CACl2=333克 CACl2

    When you measure the mass of 333 g of CaCl 2 , you are measuring 3.00 moles of CaCl 2 .
    ::当测量333克CaCl2的质量时,你测量的是3.00摩尔的CaCl2质量。

    White granules of calcium chloride in a glass dish, labeled as anhydrous calcium chloride.
    Calcium chloride is used as a drying agent and as a road deicer.

    Sample Problem: Converting Moles to Mass
    ::样本问题: 将模块转换成质量

    Chromium metal is used for decorative of car bumpers and other surfaces.  Find the mass of 0.560 moles of chromium.
    ::铬金属用于装饰汽车保险杠和其他表面,找到0.560摩尔的铬质量。

    Step 1: List the known quantities and plan the problem.
    ::第1步:列出已知数量并规划问题。

    Known
    ::已知已知

    • molar mass of Cr = 52.00 g mol
      ::Cr 的摩尔质量= 52.00克摩尔
    • 0.560 mol Cr
      ::0.560 毫毫毫立克

    Unknown
    ::未知

    • 0.560 mol Cr = ? g
      ::0.560 mol Cr =? g

    One conversion factor will allow us to convert from the moles of Cr to mass.
    ::一个转换系数将使我们能够从Cr的摩尔转换成质量。

    Step 2: Calculate.
    ::第2步:计算。

    0.560   mol Cr × 52.00   g   Cr 1   mol Cr = 29.1   g Cr

    ::0.560 摩尔 Cr×52.00克 Cr1 摩尔 Cr=29.1克

    Step 3: Think about your result.
    ::步骤3:想想你的结果。

    Since the desired amount was slightly more than one half of a mole, the mass should be slightly more than one half of the molar mass.  The answer has three because of the 0.560 mol.
    ::由于所期望的数量略高于一个摩尔的一半,质量应略高于摩尔质量的一半。 答案有三个,因为0.560摩尔。

    A similar conversion factor utilizing molar mass can be used to convert from the mass of an substance to moles.  In a laboratory situation, you may perform a reaction and produce a certain amount of a product which can be massed.  It will often then be necessary to determine the number of moles of the product that was formed.  The next problem illustrates this situation.
    ::使用摩尔质量的类似转换系数可以用来从物质质量转换成摩尔。在实验室的情况下,您可以进行反应并生产一定数量的可加集的产品。然后,通常有必要确定所产产品摩尔数量。下一个问题说明了这种情况。

    Sample Problem: Converting Mass to Moles
    ::样本问题: 将质量转换为摩尔

    A certain reaction produces 2.81 g of copper(II) hydroxide, Cu(OH) 2 .  Determine the number of moles produced in the reaction.
    ::某种反应产生2.81克铜(II)氢氧化氢,Cu(OH)2.确定反应中产生的摩尔数量。

    Step 1: List the known quantities and plan the problem.
    ::第1步:列出已知数量并规划问题。

    Known
    ::已知已知

    • mass = 2.81 g
      ::质量=2.81克

    Unknown
    ::未知

    • mol Cu(OH) 2
      ::mol Cu( OH) 2

    One conversion factor will allow us to convert from mass to moles.
    ::一个转换系数能让我们从质量转换成摩尔

    Step 2: Calculate.
    ::第2步:计算。

    First, it is necessary to calculate the molar mass of Cu(OH) 2 from the molar masses of Cu, O, and H.  The molar mass is 97.57 g/mol.
    ::首先,必须从Cu、O和H的摩尔质量中计算出Cu(OH)2的摩尔质量。 摩尔质量为97.57克/摩尔。

    2.81   g   Cu(OH) 2 × 1     mol   Cu(OH) 2 97.57   g   Cu(OH) 2 = 0.0288   mol   Cu(OH) 2

    ::2.81 g Cu(OH)2×1 mol Cu(OH)297.57 g Cu(OH)2=0.0288 mol Cu(OH)2

    Step 3: Think about your result.
    ::步骤3:想想你的结果。

    The relatively small mass of product formed results in a small number of moles.
    ::形成的产品数量相对较少,造成少量的内鬼。

     

     

     

      Practice converting mass to moles  in everyday objects in this simulation: 
    ::练习将质量转换为日用物体中的摩尔, 在此模拟中 :

     

     

    Summary
    ::摘要

    • Calculations involving conversions between moles of a material and the mass of that material are described.
      ::说明涉及材料摩尔与材料质量之间转换的计算。

    Review
    ::回顾

    1. You have 19.7 grams of a material and wonder how many moles were formed. Your friend tells you to multiply the mass by grams/mole. Is your friend correct?
      ::您有19.7克的材料, 并想知道有多少内鬼被组成。 您的朋友要您将质量乘以克/ 摩尔 。 您的朋友是否正确 ?
    2. How many grams of MgO are in 3.500 moles?
      ::3500摩尔中有多少克MGO?
    3. How many moles of H 2 O are in 15.2 grams of pure ice?
      ::15.2克纯冰中有多少个H2O的摩尔?