Chemistry 1020
化学 1020
Lab 3 Observations & Separations
实验室 3 观察和分离
Observations & Separations
观察与分离
Objectives
目标
To practice describing and recording observations during a chemical experiment
练习在化学实验中描述和记录观察结果
To learn vocabulary and numerical standards for writing observations and data
学习编写观测值和数据所需的词汇和数字标准
To perform basic solid-liquid separation techniques
执行基本的固液分离技术
Pre-lab Exercises
实验前练习
Look at the MSDS for copper (II) chloride dihydrate (this can be found in the Lab 1 materials)
查看氯化铜 （II） di水合 物的 MSDS（可以在实验室 1 材料中找到）
Answer the Pre-lab Exercises on the lab report sheet prior to coming to lab on time – they will be checked by your lab instructor before you can start your lab.
在准时来到实验之前，请回答实验成绩单上的实验前练习 - 在您开始实验之前，您的实验教师将对其进行检查。
Background
背景
Observations
观察
During a chemical reaction you will need to write down your observations of what is happening. In
在化学反应过程中，您需要写下您对所发生的事情的观察。在
general, bulleting or short phrases are sufficient. Your observations should include the qualitative descriptions that will allow you to envision what you did at a later time. You should always include:
G常规、项目符号或短短语就足够了。您的观察应包括定性描述，以便您设想您以后做了什么。您应该始终包括：
Initial observations of the materials you used at the beginning of an experiment
对实验开始时使用的材料的初步观察.
Observations of what happened during the experiment
对实验期间发生的事情的观察.
Final observations of the products
产品的最终观察.
Qualitative observations should include what you gain from your own senses – what you see and hear, and if approved by the instructor, what it feels like or smells like. You should always include:
定性观察应包括您从自己的感官中获得的收益——您所看到和听到的，如果得到教练的批准，它的感觉或气味是什么样子。您应该始终包括：
Color: white, black, blue, colorless, etc.
颜色：白色、黑色、蓝色、无色等。
Texture: thick, sticky, grainy, powder, crystal, chunk, etc.
质地：厚、粘、粒状、粉末、结晶、块状等。
Clarity: clear (see-through) or cloudy (not see-through). Note: clear does not mean colorless – think about sunglasses
净度：透明（透明）或浑浊（不透明） 注意 透明并不意味着无色 - 想想太阳镜
State: solid, liquid, or gas. Often this is implied in your texture word – if something is a white powder, it is understood to be a solid
状态：固体、液体或气体。 这通常隐含在你的质地词中——如果某物是白色粉末，它就会被理解为固体
Quantitative observations involve anything you measure – dimensions, mass, temperature, volume, etc. All quantitative observations (measurements) should have:
定量观察涉及您测量的任何东西 - 尺寸、质量、温度、体积等。所有定量观察（测量）都应具有：
The proper unit
合适的单位.
The accuracy that can be achieved with the measuring device e.g. mass to 0.01g, volume to 0.1 mL. This is important, as it will affect your significant figures in calculations.
使用测量设备可以达到的精度，例如质量为 0.01 g，体积为 0.1 mL。这很重要，因为它会影响您在计算中的重要数字。
Procedure
程序
1. Observations of a Chemical Reaction
1. 化学反应的观察
Get out your 100-mL beaker (this is not the same as a graduated cylinder!) and make sure it is clean; rinse with deionized water if needed
拿出您的 100 mL 烧杯（这与量筒不同！）并确保它是干净的，如果需要，请用去离子水冲洗.
Fill about half-way with deionized water
用去离子水填充约一半.
Using the metal scoop from your drawer, weigh out 6.5 g to 7.0 g of “Blue Crystals” (copper (II) chloride dihydrate) into a tared (zeroed) plastic weighing boat.
使用抽屉中的金属勺，称取 6.5 克至 7.0 克“蓝色晶体”（铜 （II） chloride d水合物）放入去皮（归零）塑料称量船中。
Record your initial observations on the report sheet
在报告表上记录您的初步观察结果.
Place the beaker on a white or light colored background
将烧杯放在白色或浅色背景上.
Add the Blue Crystals to the water all in one portion
将 Blue Crystals 分一份加入水中.
Let the beaker stand for about 2 minutes
让烧杯静置约 2 分钟.
Record your observations – remember a picture or diagram is worth 1000 words!
记录您的观察结果 - 记住一张图片或图表胜过 1000 个单词！
Using a glass stir rod, stir until all the crystals are dissolved and record any notable observations
使用玻璃搅拌棒，搅拌直至所有晶体溶解并记录任何值得注意的观察结果.
Take a piece of aluminum foil, approximately 3 cm x 3 cm, and loosely crumple it into a ball just so it will fit into the beaker
取一块大约 3 厘米 x 3 厘米的铝箔，将其松散地揉成一个球，以便它能放入烧杯中.
Place the Al foil ball into the solution in the beaker and record any notable observations
将铝箔球放入烧杯中的溶液中，并记录任何值得注意的观察结果.
Allow to sit for 15 minutes or longer (you may move on to other parts of the lab)
静置 15 分钟或更长时间（您可以转到实验室的其他部分）.
Stir the contents of beaker and record your final observations
搅拌烧杯的内容物并记录您的最终观察结果.
Dispose of the final solution in the labeled waste container under the hood. Stir and dump quickly to get the solid materials into the waste container.
将最终溶液丢弃在引擎盖下贴有标签的废液容器中。快速搅拌并倾倒，将固体材料放入废液容器中。
Wash the beaker in the sink – no need to dry, it will air dry just fine – conserve paper towels!
在水槽中清洗烧杯 - 无需晾干，它会自然风干就好了 - 节省纸巾！
2. Observations of a Bunsen burner
2. 本生灯的观察
Get out your Bunsen burner from under the cupboard and examine it
从橱柜下面拿出你的本生灯并检查它.
Get out your flint striker from your drawer
从抽屉里拿出你的打火石机.
Practice making a spark with the striker by pushing the flint across AND DOWN ONTO the file as the instructor has demonstrated
按照教练的演示，通过将燧石推过并向下推到锉刀上，练习与撞针产生火花.
Attach the Bunsen burner hose to the gas and open the bottom slide valve
将本生灯软管连接到燃气上并打开底部滑阀.
Turn the gas on so that you just hear it – not fully parallel to nozzle, but close
打开燃气，以便您能听到它 - 不完全平行于喷嘴，但很近.
Light the Bunsen burner and adjust gas and bottom value as needed until you see a distinct inner cone within the blue flame
点燃本生灯并根据需要调整燃气和底部值，直到在蓝色火焰中看到明显的内锥体.
Hold a copper wire with forceps.
用镊子握住铜线。
Move the copper wire, starting at the bottom of the flame, slowly up through the flame, out the top and back down again
移动铜线，从火焰底部开始，慢慢向上穿过火焰，从顶部出来，然后再向下移动.
Label the hottest and coolest locations on the diagram of the properly adjusted Bunsen burner flame on your report sheet.
在报告表上正确调整的本生灯火焰图上列出最热和最冷的位置。
Lift up the Bunsen burner by the base (the base does not get hot)
通过底座提起本生灯（底座不会变热）.
Place your thumb completely over the opening on the bottom
将拇指完全放在底部的开口上.
List a minimum of three observed changes to the flame (there are actually at least five) on your report sheet
在报告表上列出至少 3 个观察到的火焰变化（实际上至少有 5 个）.
3. Solid-Liquid Separations – Decanting, Gravity Filtration, and Vacuum Filtration.
3. 固液分离 – 倾析、重力过滤和真空过滤。
First, you will make one mixture that you will separate using three different methods.
首先，您将制作一种混合物，您将使用三种不同的方法进行分离。
Add 20 mL of calcium chloride solution (0.2 M CaCl2) to a 50 mL beaker.
将 20 mL 氯化钙溶液 （0.2 M CaCl2） 添加到 50 mL 烧杯中。
SLOWLY add 20 mL of sodium carbonate solution (0.2 M Na2CO3) while mixing well with a glass stirring rod. (Mixing too quickly results in smaller particle sizes that are harder to filter and take longer to settle.)
缓慢加入 20 mL 碳酸钠溶液（0.2 M Na2CO3），同时用玻璃搅拌棒充分混合。（混合过快会导致颗粒尺寸更小，更难过滤，需要更长的时间才能沉降。
Stir 1 minute with the glass stirring rod
用玻璃搅拌棒搅拌 1 分钟.
Decanting
醒酒
The simplest method of separating a liquid from a solid is by decanting: pouring off the clear liquid while the heavier solid stays on the bottom. This method works well for a mixture where the solid is sufficiently dense to settle on the bottom.
将液态ID 与固体分离的最简单方法是醒酒：倒出透明液体，而较重的固体留在底部。这种方法适用于 固体密度足以沉淀在底部的混合物。
Fill a test tube ¾ full with the stirred mixture that you made above
将试管中装满 3/4 的搅拌混合物.
Allow to settle for several minutes. You may move on to the next parts of the lab while waiting.
静置几分钟。在等待期间，您可能会继续进行实验室的下一部分。
Decant the liquid into another (clean) beaker
将液体倒入另一个（干净的）烧杯中.
Record your observations on your report sheet, including information on how clear the decanted liquid is and how dry the solid is
在报告表上记录您的观察结果，包括有关倾析液体的透明度和固体干燥程度的信息.
Gravity Filtration
重力过滤
Gravity filtration makes use of some type of filter media – we will be using filter paper. Much like a coffee filter, the purpose of the filter is to trap the solids while allowing the liquid to pass through by gravity. Filter papers come in all different grades providing various levels of filtering effectiveness. In any case, the liquid that comes through the filter (whether it is clear or still cloudy) is called the filtrate. The solid that is trapped on the paper can be an insoluble solid, like sand, or a newly formed solid that results from a chemical reaction when two chemicals are mixed, called a precipitate.
重力过滤使用某种类型的过滤介质 - 我们将使用滤纸。与咖啡过滤器非常相似，过滤器的目的是捕获固体，同时允许液体通过重力通过。滤纸有各种不同的等级，提供不同程度的过滤效果。无论如何，通过过滤器的液体（无论是透明的还是仍然浑浊的）称为滤液。被困在纸张上的固体可以是不溶性固体，如沙子，也可以是两种化学物质混合时发生化学反应产生的新形成的固体，称为沉淀物。
Get your 125-mL Erlenmeyer flask and funnel from the drawer
从抽屉中取出 125 mL 锥形瓶和漏斗.
Get a piece of the larger circular filter paper
获取一块更大的圆形滤纸.
Fold the filter paper in half
将滤纸对折.
Fold the paper again to almost in quarters, holding back one straight edge so a narrow “V” shape is visible. This is done because if you fold it into perfect quarters it will not fit our funnels very well
再次将纸张折叠至几乎四分之一，保留一个直边，以便看到狭窄的“V”形。这样做是因为如果你把它折叠成完美的四分之一，它就不会很好地适合我们的漏斗.
Tear off a small piece of the upper short corner. This allows the paper to lay flat against the funnel near the fold.
撕掉一小块上短角。这样，纸张就可以平放在靠近折叠的漏斗上。
Open filter paper to the larger side – three layers on one side, one layer on the other – and place it in the funnel
将滤纸打开到较大的一侧 - 一侧有三层，另一侧有一层 - 并将其放入漏斗中.
Wet the filter paper with deionized water so it stays in funnel; pour off any excess water
用去离子水润湿滤纸，使其留在漏斗中;倒掉多余的水.
Stir the mixture in your 50 mL beaker
在 50 mL 烧杯中搅拌混合物.
Pour about half (10 mL) of the remaining mixture into the filter paper
将大约一半 （10 mL） 剩余的混合物倒入滤纸中.
Allow time for the liquid to filter through. Record how long this takes.
留出时间让液体通过 Record how time this takes （记录这需要多长时间） 进行过滤。
Record your observations of the filtered liquid (the filtrate) and the solid
记录您对过滤液体（滤液）和固体的观察结果.
Leave the Erlenmeyer flask, funnel and filter paper while you do the next part
留下锥形瓶、漏斗和滤纸，然后进行下一部分.
Vacuum Filtration
真空过滤
Vacuum filtration also uses a filter media, and again we will be using filter paper. In this case you will use a special funnel called a Buchner funnel. Each bench should have a vacuum filtration set-up already assembled. This filter paper does not need to be folded – it is already cut to the proper size of the funnel.
真空过滤也使用过滤介质，我们将再次使用滤纸。在这种情况下，您将使用一个名为 Buchner 漏斗的特殊漏斗。每个工作台都应已组装好真空过滤装置。这种滤纸不需要折叠 - 它已经被切割成漏斗的适当大小。
Stir the remaining mixture in your 50 mL beaker
在 50 mL 烧杯中搅拌剩余的混合物.
Inform the instructor your bench is ready to do the vacuum filtration.
告诉教练您的工作台需要进行真空过滤。
The instructor will make sure the vacuum apparatus is set up correctly and give directions.
教练将确保真空设备设置正确并给出指导。
When told by the instructor, swirl the beaker to suspend the solid and pour onto the filter paper
当讲师告诉时，旋转烧杯以悬浮固体并倒入滤纸上.
Record how long it takes for the filtrate to be separated from the solid.
记录滤液与固体分离所需的时间。
Rinse any residual solid out onto the filter with the deionized water bottle
用去离子水瓶将残留的固体冲洗到过滤器上.
Allow vacuum to run for a few minutes
让真空运行几分钟.
Feel the outside of the vacuum flask that now has the filtrate in it
感受真空瓶的外部，现在里面有滤液.
Record your observations on the report sheet, making any notable comparisons to the other methods
在报告表上记录您的观察结果，与其他方法进行任何显着的比较.
Turn off the vacuum
关闭真空吸尘器.
Remove the top half of the filter funnel to remove the vacuum filter paper.
取下过滤漏斗的上半部分以去除真空滤纸。
Compare the filter paper to the gravity filter paper
将滤纸与重力滤纸进行比较.
Dispose of both filter papers in garbage can – these are not hazardous
将两张滤纸丢弃在垃圾桶中 - 这些滤纸无害.
Remove the two black stoppers (not the tubing!) to empty the contents of the vacuum flask into the sink.
取下两个黑色塞子（不是管子），将真空瓶中的内容物倒入水槽中。
Rinse the beaker with 1-2 drops of 10% HCl to remove cloudiness. Rinse with water.
用 1-2 滴 10% HCl 冲洗烧杯以去除混浊。用水冲洗。
4. Solid-Liquid Separations – Centrifuge
4. 固液分离 – 离心机
Some mixtures do not separate well by decanting or filtering. Often the particles are so small that they stay suspended. Their small size can either pass right through the openings in filter paper or clog up the openings. An alternative method of separation uses centrifugal force to separate the solid by density. Centrifugal force is not gravity! A centrifuge creates centrifugal force by spinning. Whenever you spin something at a high rate of speed, the more dense material or item will be pushed to the outside. Like a child on a merry-go-round at a playground, the child who is denser than air gets pushed to the outside. A centrifuge is a common piece of laboratory equipment that is used in the first step of many blood tests.
有些混合物不能通过倾析或过滤很好地分离。通常颗粒非常小，以至于它们保持悬浮状态。它们的小尺寸可以直接穿过滤纸的开口，也可以堵塞开口。另一种分离方法是使用离心力按密度分离固体。Ce阻力不是重力！离心机通过旋转产生离心力。 每当您高速旋转某物时，更密集的材料或物品就会被推到外面。就像一个孩子在游乐场的旋转木马上一样，密度比空气大的 c hild 被推到外面。离心机是一种常见的实验室设备，用于许多血液测试的第一步。
Measure 3 mL of Congo Red solution directly into a test tube. (Hold the test tube next to a 10-mL graduated cylinder and fill the test tube until the liquid is level with the 3 mL mark of the graduated cylinder. Use the eye dropper from your drawer to dispense the Congo Red. Clean the eye dropper by removing the bulb and flushing with water)
将 3 mL 的 Congo Red 溶液直接量入试管中。（将试管放在 10 mL 量筒旁边，然后填充试管，直到液体与量筒的 3 mL 标记齐平。使用抽屉中的滴管分配刚果红。通过取下灯泡并用水冲洗来清洁吸管）.
Add 3 mL of 10% hydrochloric acid (10% HCl) directly into the same test tube. (Still holding the test tube up next to the 10-mL graduated cylinder, add HCl up to the 6 mL mark)
将 3 mL 10% 盐酸 （10% HCl） 直接加入同一试管中。（仍将试管放在 10 mL 量筒旁边，添加 HCl 至 6 mL 标记）.
Mix using a stirring rod in a vertical motion and record your observations
使用搅拌棒以垂直运动混合并记录您的观察结果.
Bring the test tube to the instructor’s station to run through the centrifuge
将试管带到教练站，让离心机穿过.
The instructor will have you load your test tube in and a second test tube with the same volume of water directly opposite to act as a balance tube
教练会让您装入试管，并在正对面放置第二根具有相同水体积的试管作为平衡管.
After centrifuging, record your observations
离心后，记录您的观察结果.
Re-suspend the material by mixing thoroughly with a stirring rod
用搅拌棒充分混合，重新悬浮材料.
Dispose of this liquid mixture in the sink
将这种液体混合物丢弃在水槽中.
Rinse and clean the test tube
冲洗并清洁试管.