Class 11 Experiment Chemistry | Cutting, Bending Drawing jet from glass tube | Theory and Practical

00:09:03
https://www.youtube.com/watch?v=6oabC6KaUpQ

Summary

TLDRIn this video, the presenter demonstrates three essential chemistry experiments for class 11 students: cutting a glass tube, bending a glass tube, and drawing a jet from a glass tube. The video provides detailed instructions on how to perform each experiment safely and effectively. For cutting, students learn to measure, mark, and use a triangular file to create a scratch before breaking the tube. Bending involves heating the tube at a specific point and ensuring a clean angle. Finally, drawing a jet requires heating the tube until soft and pulling it apart to create a desired bore size. The video emphasizes the importance of safety precautions and proper techniques throughout the experiments.

Takeaways

  • ✂️ Cut a glass tube by marking and scratching it carefully.
  • 🔥 Fire polish the ends for smoothness after cutting.
  • 🔄 Bend a glass tube at a 90-degree angle with steady heating.
  • 🖐️ Keep one hand fixed while bending to avoid shaking.
  • 💧 Draw a jet by heating and pulling the glass tube apart.
  • 📋 Document experiments with aim, procedure, and diagrams.
  • ⚠️ Always follow safety precautions when handling glass.
  • 📏 Measure accurately for precise cuts and bends.
  • 🧪 Practice these techniques in school labs for hands-on learning.
  • 📖 Include all necessary details in your lab report.

Timeline

  • 00:00:00 - 00:09:03

    In this video, the presenter introduces three important chemistry experiments for class 11: cutting a glass tube, bending a glass tube, and drawing a jet. The first experiment involves cutting a 10 cm glass rod using a triangular file to create a strong scratch before breaking it into two halves. The ends can be smoothed using fire polishing. The second experiment demonstrates bending a glass tube at a 90-degree angle by heating it at a specific point and ensuring a steady hand to avoid kinks. The final experiment shows how to draw a jet from a glass tube by heating and pulling the ends apart, followed by cutting to achieve the desired bore size and fire polishing the end. The presenter emphasizes the importance of writing down the procedures, precautions, and diagrams for each experiment in a lab notebook.

Mind Map

Video Q&A

  • What is the first experiment discussed in the video?

    The first experiment is cutting a glass tube of length 10 centimeters.

  • How do you cut a glass tube?

    You measure 10 cm, mark it, use a triangular file to make a scratch, and then break it gently.

  • What is the purpose of bending a glass tube?

    Bending a glass tube is typically done to create delivery tubes.

  • What angle is the glass tube bent to?

    The glass tube is bent to an angle of 90 degrees.

  • What is the final experiment shown in the video?

    The final experiment is drawing a jet from a glass tube.

  • What should you do to smooth the ends of the glass tube after cutting?

    You can fire polish the ends by heating them in a flame.

  • What precautions should be taken while bending the glass tube?

    Keep one hand fixed while turning the other to avoid shaking.

  • How do you create a jet from a glass tube?

    Heat the tube until soft, pull the ends apart, and then cut to the desired size.

  • What should be included in the lab report for these experiments?

    The report should include the aim, apparatus used, procedure, precautions, and diagrams.

  • What is fire polishing?

    Fire polishing is the process of heating the ends of the glass tube to smooth them.

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  • 00:00:00
    [Music]
  • 00:00:03
    hi guys
  • 00:00:04
    uh welcome to my channel in this video
  • 00:00:06
    i'm going to discuss with you
  • 00:00:08
    three important experiments of class
  • 00:00:10
    11th chemistry which are done that is
  • 00:00:11
    cutting a glass tube
  • 00:00:13
    uh bending a glass tube and drawing a
  • 00:00:15
    jet so you can just follow the
  • 00:00:17
    instructions
  • 00:00:18
    uh look for all the precautions listen
  • 00:00:20
    carefully
  • 00:00:21
    and then go to your school labs to
  • 00:00:23
    practice the same so let us begin
  • 00:00:25
    so our first experiment is cutting a
  • 00:00:27
    glass rod
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    of length 10 centimeter right so
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    the first thing to check is i will take
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    a smooth end
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    uh i'll feel this end of the glass rod
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    this is a smooth end so i'll start from
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    here and measure
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    10 centimeter from here using a scale
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    and mark that end with the marker
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    so i'm keeping
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    this here and 10 centimeter i'll make a
  • 00:00:56
    mark
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    this is a 10 centimeter mark and now i'm
  • 00:01:01
    going to make a cut here
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    using this triangular file this is a
  • 00:01:05
    triangular file
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    it is wedge shape it has these three you
  • 00:01:09
    can see
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    uh surfaces with
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    this is a rough surface like a sandpaper
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    so
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    we can use this surface to rub and
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    smoothen
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    a particular end okay if your end is not
  • 00:01:23
    smooth if the end of the glass rod is
  • 00:01:25
    not smooth
  • 00:01:25
    it can be rubbed like this with this
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    file to make it smooth
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    okay so now i'm going to make a hold the
  • 00:01:32
    glass tube
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    very firmly with this
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    finger and thumb not excess pressure
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    neither too lightly
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    and hold this file this way and make a
  • 00:01:43
    one
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    strong scratch one strong scratch
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    in case you feel one is not strong
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    enough you can repeat
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    one on the same point this scratch
  • 00:01:54
    should not be
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    too strong otherwise this glass tube
  • 00:01:58
    will crash or break
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    and you will not give it repetitive
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    scratches also
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    there should be a strong scratch at one
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    point and now i'm going to
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    hold this between these two hands
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    this is the scratch point i'll face it
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    away from me
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    keep the thumb and finger and just with
  • 00:02:16
    the soft pressure break it and i get
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    these two two halves this is a 10
  • 00:02:22
    centimeter
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    uh tube and i will feel the
  • 00:02:26
    ends the ends are smooth in case they
  • 00:02:29
    are not
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    as i told you you can rub it or
  • 00:02:33
    we can do fire polishing fire polishing
  • 00:02:36
    is heating it in the
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    flame fine you can fire polish the end
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    like this
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    fire polishing means i'm going to heat
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    it in the flame
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    so that the ends get rounded you study
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    this fire polishing
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    in your theory as well in liquid state
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    chapter
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    so i am just going to rotate this in
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    flame
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    and the end is rounded
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    the end gets rounded right and smooth
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    similarly if the other end is also
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    not smooth i can heat it in the flame
  • 00:03:13
    keep rotating so as to
  • 00:03:16
    smoothen that end
  • 00:03:20
    and please be careful
  • 00:03:24
    cool the tube before you handle it
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    in between two such steps so i have fire
  • 00:03:31
    polished means i've
  • 00:03:33
    rounded the edges and this is a
  • 00:03:36
    glass tube with 10 centimeter length
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    cut right
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    so you can observe this is a 10
  • 00:03:46
    centimeter long
  • 00:03:47
    tube plus tube cut right now
  • 00:03:50
    we will discuss how to bend a glass tube
  • 00:03:53
    at an angle of 90 degree
  • 00:03:55
    why do we need to bend we generally bend
  • 00:03:57
    glass tubes to create delivery tubes
  • 00:04:00
    so let us go ahead so this is a glass
  • 00:04:03
    tube i have taken a glass tube
  • 00:04:05
    right and this is the long glass tube
  • 00:04:07
    i'm going to bend this last tube at an
  • 00:04:09
    angle of 90 degree
  • 00:04:10
    at an angle of 90 degree so just say
  • 00:04:14
    i'm going to heat this at the point i
  • 00:04:15
    want to bend
  • 00:04:17
    with constant swirling in the
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    non-rivenous part of the flame
  • 00:04:21
    i'm going to heat this constantly like
  • 00:04:23
    this
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    and the moment it feels soft
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    and please see that you focus heat at
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    one point
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    only you don't let heat move
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    and now bend it to an angle of 90
  • 00:04:38
    i'll check the angle by putting it here
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    and as still hot i can set the angle
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    this is a 90 degree angle i am checking
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    it across the edge of this
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    tile the surface okay and now let it
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    cool
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    this is your bent glass tube
  • 00:04:58
    so i'm showing you another glass tube
  • 00:05:00
    again and telling you the precautions
  • 00:05:02
    the first precaution is you should keep
  • 00:05:03
    swelling like this
  • 00:05:05
    the second precaution is
  • 00:05:08
    the second precaution is when you have
  • 00:05:10
    to bend it
  • 00:05:11
    you will only turn one hand not
  • 00:05:15
    both you will not turn both hands in
  • 00:05:18
    only one keep one fixed and with
  • 00:05:21
    one see i'm just turning one with one
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    without any shaking like this there
  • 00:05:27
    should be no shaking
  • 00:05:28
    because if there's a shaking there will
  • 00:05:30
    be a kink at this point this
  • 00:05:32
    point might get blocked so there should
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    be no shaking of hand
  • 00:05:35
    uh you will not move see you will not
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    move both the hands like this
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    you will keep one hand fix and just move
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    one
  • 00:05:42
    right this is going to give you a very
  • 00:05:44
    neat clean bend
  • 00:05:45
    so this was bending a tube and now we're
  • 00:05:48
    going to proceed with how to draw a jet
  • 00:05:51
    how to draw a jet from a glass tube so
  • 00:05:53
    again i am taking a glass tube
  • 00:05:55
    and heating it in this non-luminous part
  • 00:05:57
    of the flame
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    with constant swirling
  • 00:06:01
    and the moment it becomes soft
  • 00:06:05
    i'll pull the two ends apart
  • 00:06:14
    see it has become soft and now i'm going
  • 00:06:16
    to pull the two ends
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    apart right and
  • 00:06:21
    let this end cool and now depending
  • 00:06:25
    on depending upon how much
  • 00:06:28
    size bore i want what is the size of the
  • 00:06:31
    hole i want at that end
  • 00:06:32
    i will be making a cut on this
  • 00:06:36
    so i'm going to make a cut with this
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    wedge
  • 00:06:39
    and depending if i want a bigger hole
  • 00:06:42
    i'll cut it towards this end
  • 00:06:44
    if i want a smaller hole towards the tip
  • 00:06:46
    and then i can
  • 00:06:48
    fire polish this end to smoothen this
  • 00:06:51
    end
  • 00:06:51
    i can fire polish to smoothen this end
  • 00:06:56
    and this is a jet
  • 00:07:00
    prepared so i'll show you uh how this is
  • 00:07:03
    working like a jet see i'm going to
  • 00:07:07
    pour water into this
  • 00:07:11
    and uh you can see
  • 00:07:14
    this is now working like a jet
  • 00:07:21
    so you can see this is behaving like a
  • 00:07:24
    jet
  • 00:07:24
    i'm sharing with you how to write down
  • 00:07:27
    the
  • 00:07:28
    cutting bending experiment in your copy
  • 00:07:30
    this is the right hand side page
  • 00:07:32
    you will write down to cut a glass tube
  • 00:07:34
    of 10 centimeter length
  • 00:07:36
    and then the procedure and then the
  • 00:07:40
    precautions this is to be written on the
  • 00:07:43
    right hand side
  • 00:07:44
    page on the left hand side page again
  • 00:07:47
    aim
  • 00:07:48
    apparatus used
  • 00:07:52
    and diagrams this is the next experiment
  • 00:07:58
    to bend a glass tube at an angle of 90
  • 00:08:01
    degree
  • 00:08:02
    again writing aim procedure
  • 00:08:07
    and precautions
  • 00:08:12
    this is the left hand side page
  • 00:08:17
    aim apparatus
  • 00:08:24
    diagrams
  • 00:08:29
    this is the third experiment to draw a
  • 00:08:32
    glass jet
  • 00:08:34
    again aim
  • 00:08:38
    apparatus
  • 00:08:41
    diagram
  • 00:08:52
    and this is the right hand side page
Tags
  • chemistry
  • experiments
  • glass tube
  • cutting
  • bending
  • jet
  • fire polishing
  • safety precautions
  • class 11
  • lab report