KR100750503B1 - Experimental apparatus to measure molarity or normality - Google Patents

Abstract

An experimental apparatus for measuring molarity or normality is provided to produce solution with the concentration proximate to a target level by correcting a mass measurement error by regulating the volume. An experimental apparatus for measuring molarity or normality is composed of a reference mark line(15) for measuring molarity or normality and indication scales(21,22,23,31,32,33) marked at the upper end of the reference mark line according to one of groups for decrease concentration intervals of 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10% and marked at the lower end of the reference mark line according to one of groups for increase concentration intervals of 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%.

Description

Laboratory instrument for measuring molarity or normal concentration {EXPERIMENTAL APPARATUS TO MEASURE MOLARITY OR NORMALITY}

1 is a partial view and a scalpel to which an embodiment of the present invention is applied;

2 is a detail view of the measuring cylinder and one embodiment to which an embodiment of the present invention is applied;

3 is a pipette and a partial detail to which an embodiment of the present invention is applied.

<Description of Major Symbols in Drawing>

10: measuring flask

40: measuring cylinder

70: pipette

15, 45, 75: marker lines for each instrument

21, 22, 23, 51, 52: indication scales above the marker line

31, 32, 33, 61, 62, 81, 82: indication scales below the marker line

The present invention relates to an experimental instrument for measuring molarity or normal concentration, and more particularly, in an experimental instrument for containing or transferring a solvent or a solution, a reference line for measuring the molar concentration or normal concentration is displayed, and the standard On the basis of the molar concentration or the normal concentration determined by the size of the indicator line, an indication interval of decreasing concentration interval for the concentration is at the top of the reference indicator line or at least one indication interval of an increasing concentration interval for the concentration is at the bottom of the reference indicator line. For measuring marked or normal concentrations It relates to an experimental apparatus.

Laboratory instruments used to contain or transfer a certain amount of solvent or solution include meas flasks (or volumetric flasks), mes Cylinders, beakers, various types of flasks, pipettes, and the like. These instruments may be used to prepare a desired concentration of solution, or other solutions may be prepared using standard solutions. In the process of preparing the desired target concentration, it must be possible to accurately match the exact moles of solute with the amount of solvent used, but this is not easy. It is a reality to use a little more or less than the desired amount, and even if there is a slight difference from the desired target concentration, the degree of difference in the experiment is acceptable. However, even if there is a difference from the desired target concentration, it is necessary to know the exact concentration of the actually prepared solution, and experiment with the actual concentration to obtain more accurate experimental data.

In many laboratories related to chemistry or biotechnology, a volumetric solution or a measuring cylinder is used in the preparation of a certain concentration of solution. In this case, great care is taken to dissolve the solute and add a solvent to fill the marker line. If you're short on, you may want to add a little bit more to match it and then cross the marker line. In such a case, it is too cumbersome to dissolve the solute further since it is below the desired concentration, and it is very difficult to measure the mass of the added solute. However, when used as it is a target concentration may cause a problem due to the difference with the actual concentration. In other words, knowing the target concentration and the actual concentration in the proximity range, not the target concentration, is necessary to obtain more accurate results. Therefore, many experimenters are repeating the process of throwing away the solvent if it exceeds the marker line and preparing a solution of the desired target concentration.

In this case, the economic damage caused by the overuse of the drug and the labor loss to rebuild it because of the overuse of the drug can not be reused. Furthermore, if the concentration you are trying to make is the process of performing the next step using a product in the middle of an experiment, you cannot discard it if you do not know the exact concentration. We will continue our experiments, or we will have to spend so much time removing the solvent again to get the solute to get the target concentration again, and we can't guarantee that we won't make any mistakes.

In the laboratory, it is a reality that relies on more careful attention and more skilled researchers.

The present invention is to solve the above problems, in the laboratory apparatus for containing or transferring a solvent or solution marked with a marker line to know the amount of the solvent or solution, the indication scale is to the top or bottom of the marker line It can be displayed for more than one day, and the marking interval can be set in such a way that the measurement of molar concentration is very easy, thereby preventing the waste of reagents, which are discarded unnecessarily, as well as the accuracy of the experiment, and contributing to environmental protection. An object of the present invention is to provide an experimental apparatus that can be used.

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The present invention for achieving the above object is a laboratory apparatus for containing or transferring a solvent or a solution, the reference line for measuring the molarity or normal concentration is displayed, the molar concentration or normal concentration determined by the size of the reference line The concentration of 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10% of the concentration decreases at the top of the reference indicator line. One is selected from a crowd of concentration intervals or at the bottom of the reference line 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% and 10 for the concentration. For measuring molar or normal concentrations in which more than one indicator is selected from the crowd at concentration intervals of increasing concentration of% It relates to an experimental apparatus.
In the present invention, the laboratory apparatus is preferably selected from the group consisting of beakers, flasks, measuring cylinders and pipettes, and more preferably the flask is a measuring flask such as a round bottom flask or a wide bottom flask.
In addition, the indication scales displayed at the top or bottom of the marker line are preferably formed at the top and bottom one, and the top of the reference indicator line based on the molar concentration or normal concentration determined by the size of the reference indicator line. Is a concentration interval in which the concentration of 1% with respect to the concentration decreases, and a concentration interval in which the concentration of 1% with respect to the concentration increases is displayed at the lower end of the reference indicator line.

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In order to prepare a solution of the desired molarity, it is not easy to accurately measure the amount of solute and to put the correct amount of solvent. On the other hand, the difference of about 5% of the target concentration even if it is not the desired molar concentration is acceptable in experiments unless it is a very special case, and sometimes there is no problem even if the difference is more than that. It is important to know the value of the actual concentration, because knowing the exact concentration of the target concentration outside of a certain range will give a more accurate result for the next step in which the solution will be used.

In the present invention, in the experimental apparatus for holding or transferring a solution or solvent, by indicating the indicator scale at a specific interval on the top or bottom of the marker line, it is possible to measure the concentration more accurately, and to easily calculate the actual concentration This prevents the loss of drugs and preserves the environment.

If a meniscus is formed on the marker line to produce the target concentration, if the solvent is filled only to the bottom of the marker line or beyond the marker line, the amount of the insufficient portion or the overflow portion is known. In order to display a specific interval at the lower part or the upper part of the marker line, a more accurate concentration can be obtained. The interval of the indication scale can be produced, for example, at an interval of 1% of the target concentration. When preparing a molar concentration (mol / l) of a constant target concentration, when using a 500 ml volumetric flask, a concentration exceeding 1% of the target concentration should be added up to 4.95 ml below the marker line. If the concentration exceeds 2% of the target concentration is to be added up to 9.80 ㎖ below the marker line, another indication scale is indicated in this area, and the concentration below 1% of the target concentration can be put up to 5.05 ㎖ above the marker line. In this area, the indication scale is displayed. A concentration less than 2% of the target concentration is achieved by putting up to 10.20 ml above the marker line, so another indication scale is displayed in this area. In this way, the indication scale should be below 14.56 ml for more than 3%, 19.23 ml for more than 4% and 23.81 ml for more than 5%, 15.46 ml for less than 3%, 20.83 ml for less than 4% The indication scale should be displayed on 26.32 ml (for example, in the case of 1%, if the target concentration t M and the actual concentration (t ± 0.01t) M, the solution of the target concentration is 500 ml (t ± At 0.01 t) = {1000 t / (500 ± x)}, the amount of solvent added to or lacking in it may be calculated as x. For 2%, the target concentration t M, the actual concentration (t ± 0.02 t) At M, if the solution of the target concentration is 500 ml (t ± 0.02 t) = {1000 t / (500 ± x)}, it is calculated by the amount of the solvent added to or lacking in x as x. Accordingly, the intervals of the indication scales do not come out at the same intervals (there is a constant value regardless of the value of t), and the calculated values are placed in the third digit below the decimal point in ml. This value is rounded off, but it is generally considered that the decimal point is not taken into account or calculated as a significant number up to the first digit after the decimal point).

When the indicator scale is indicated as above, even if the amount of solvent added is not exactly aligned with the marker line, the molarity of the solution to be used can be easily measured through the indicator scale on the marker line or the indicator scale below. Can be more accurately known. Although it is set as 1% space | interval from the above, a finer space | interval may be made as needed, and it is obvious that it is within the scope of the present invention from a viewpoint of those skilled in the art that it may make a space | interval wider as needed. In addition, even in the case of 1% interval, even if the meniscus is not exactly formed in the indicated scale, even if the amount calculated by the eye mass, the range of the error is greatly reduced, so there is no problem in the experiment.

Although only molar concentrations have been described above, those skilled in the art can readily appreciate that the molar concentration can be applied to normal concentrations. For reference, in the case of the molar concentration, the indicated indication scale based on the molar concentration may be used as it is. Since water is typically used as a solvent, the volumetric flask described above may be filled with 500 ml of water, and then the solute may be prepared to produce a desired molal concentration. However, since it is difficult to accurately match the amount of water to be added, it is easy to calculate the concentration by adding or subtracting 1% or 2% of the target concentration more accurately after the amount of water added through the indication scales as in the present invention. . If the solvent is different, it is possible to calculate the target concentration through density, etc., and easily calculate a more accurate concentration immediately by subtracting or adding a certain percentage of the concentration.

Hereinafter, with reference to the drawings will be described embodiments of the present invention in more detail. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

1 shows a scalpel and a partial detail to which an embodiment of the present invention is applied. The volumetric flask (10) is of various shapes, usually made of hard glass, pyrex glass, quartz glass, etc., and usually thins the neck of the flask with a flat bottom (to ensure accurate reading of the scale). The cover line 15 is attached. When the liquid is added and the bottom of the meniscus on the liquid level is aligned with the scale at a certain temperature, a certain volume of this flask is filled. It is always used to make standard solutions. The size is usually 10-1,000 ml. The volumetric volume of the flask is determined by weighing it with water or mercury. In the present invention, the indication scales 31, 32, and 33 may be displayed on the lower portion of the marker line 15 to measure a slightly higher concentration than the target concentration, and the indicator scales 21, on the upper portion of the marker line 15. 22, 23) were displayed to allow measurement of a concentration slightly lower than the target concentration. The interval between these indicators is preferably 1% of the target concentration, but is not necessarily limited thereto. For larger doses, the interval may be 0.5%. For molar concentrations of a dose of 10 ml (for example, 10 ml), the indicator should be drawn below the marker line by a difference of 0.099 ml for concentrations above 1% of the target concentration, but to indicate this difference. Is not physically easy), it is also within the scope of the present invention to slightly increase the spacing. In addition, it will be apparent that the number of the indication scales can be formed as needed, but the interval of the indication scales can only be changed slightly.

The volumetric volumetric flasks that are commonly used are 10, 20, 25, 50, 100, 200, 250, 500, 1000 and 2000 ml, and 10, 50, 100, 250, 500 and 1000 ml are used. The following table shows the amount to determine the position to display the indication scale at 1% intervals of the target concentration based on these (unit is ml, significant figures up to the first digit after the decimal point or if necessary, the number is adjusted). possible).

Unit: ml Reference mark (ml) 10 50 100 250 500 1000 Indicator scale above the cover line One% 0.101 0.505 1.010 2.525 5.051 10.101 2% 0.204 1.020 2.041 5.102 10.204 20.408 3% 0.309 1.546 3.093 7.732 15.464 30.928 4% 0.416 2.083 4.167 10.417 20.833 41.667 5% 0.526 2.632 5.263 13.158 26.316 52.632 Indication scale below cover line One% -0.091 -0.495 -0.990 -2.475 -4.950 -9.901 2% -0.196 -0.980 -1.961 -4.902 -9.804 -19.608 3% -0.291 -1.456 -2.913 -7.282 -14.563 -29.126 4% -0.385 -1.923 -3.846 -9.615 -19.231 -38.462 5% -0.476 -2.381 -4.762 -11.905 -23.810 -47.619
The change in the amount of volume according to the scale according to the change of each concentration with respect to each reference indicator line of Table 1 is shown in detail. Negative numbers in the table indicate a reduced volume in the volume of the reference line. From the table, the indicator scale above the indicator line is the amount of volume exceeded the reference volume, and the indicator scale below the indicator line indicates the amount of volume reduced than the reference volume. As described above, the experimental apparatus of the present invention changes in volume according to each scale. This is due to the fact that the experimental instrument is a concentration measurement instrument, not a volume measurement instrument.

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The indication scales are displayed on the upper and lower portions of the marker line 15 by allowing the difference of the above capacities. Practical examples will illustrate the effectiveness of the present invention.

When making a 0.100 M solution using a 1000 ml volumetric flask, if the solvent is not near the marker line and the meniscus is formed at the first indicator scale below the marker line, the concentration is calculated as 0.101 M. If the meniscus is formed at the third indication scale, it is calculated as 0.103 M, which is very close to the actual concentration. In addition, if the meniscus is formed in the middle of the marker line and the first indicator scale above the marker line and reaches the first indicator scale above the marker line, it should be calculated as 0.0995 M and proceed with the experiment. Becomes Even when the concentration is 0.025 M, when the solvent is added to the indication scale at the 1% position, 0.02525 M or 0.02475 M can be easily calculated to be close to the actual concentration. In the case of 1 M solution, it can be calculated as 1.01 M or 0.99 M, etc. It is very easy to calculate and experiments using the actual concentrations closer to it can be more accurate the overall experimental results.

In general, it will be convenient to manufacture one or two of the above indication scales, but it is obvious that the technical idea of the present invention is not limited thereto.

2 shows a partial cylinder 40 and a partial cylinder 40 to which an embodiment of the present invention is applied. Also known as graduated cylinder, it is a cylindrical container made of glass. For stability, the bottom is flat. When measuring, it is erected vertically, the liquid is poured, and the height of the liquid level is read by the graduations engraved on the cylindrical surface. In the case of the measuring cylinder, graduations are engraved at regular intervals below the volume to be used. The intervals of the graduations are intervals having a constant volume size. That is, it is difficult to know the exact concentration when the scale exceeds the scale when making a solution of the target molar concentration using this, and even if the scale is not exceeded, the calculation of the molar concentration is simply performed with the scale engraved on the measuring cylinder. It is not immediately available and it is also difficult to determine an immediate or accurate amount in the calculation of molarity because the amount of each increase or decrease is different for 1% to 5% or more differences. In particular, this is a problem because the capacity of the measuring cylinder is large or the interval of the graduation is different in the basic unit for each measuring cylinder. The technical idea of the present invention is further simplified. The indication scale 51 is displayed where the molar concentration of about 1% decreases to the top of the indicator line 45, and the indication scale 52 is indicated where the molar concentration of about 2% decreases. The indication scales 61 and 62 are also displayed at the bottom of the. These indicator scales do not necessarily need to be formed near the 50 ml marker line as shown in this figure, and may be formed around 40 ml if necessary. In the case of a measuring flask, the technical spirit of the present invention may be more practical, but in the case of a large measuring cylinder, such separate indicating scales may be very useful.

3 is a partial detailed view of a pipette 70 to which an embodiment of the present invention is applied. In the case of the pipette 70, there is a marker line 75 corresponding to the dose, and the indication scales 81 and 82 may be displayed below the marker line 75 in order to know a more accurate dose. Of course, the indication scale may also be displayed on the top of the cover line 75, but the lower part may be sufficient due to the nature of the pipette. Pipettes are generally 1, 2, 3, 5, 10, 15, 20, 25 ml, and various pipettes may be used to transfer the solution or solvent to suit the appropriate amount, but in this case flows completely. In many cases, if the technical spirit of the present invention is applied in order to know the state of the actual thing that is not a target, it will be more accurate to reduce the process than to fit it through several operations. Is much advantageous. Of course, it is advantageous in terms of time, material, and environmental.

The present invention is not limited to the above-described specific preferred embodiments, and those skilled in the art can easily modify the present invention without departing from the gist of the present invention as claimed. It is obvious that such modifications are within the scope of the present invention. For example, the interval for adjusting the degree of concentration of more than or less than the range can be adjusted according to the capacity and taking into account the convenience in manufacturing, but these are within the scope of the technical idea to be pursued in the present invention. In the experimental apparatus to be applied, it is intended to say that the experimental apparatus to contain any substance is sufficient to be applied even if it is not yet commercialized, and this is within the scope of the technical idea of the present invention. Is that.

According to the present invention described above, in preparing a solution such as a constant molarity that is a target in the laboratory, it is possible to solve the problem of not knowing the exact molarity, etc. due to problems such as over-dose of the solvent, this This prevents the waste of important reagents and intermediates in the experiment, improves the work efficiency of the experiment, and contributes to environmental conservation by reducing discarded chemicals. In addition, the error of the mass measurement can be corrected by adjusting the volume to prepare a solution closer to the target concentration.

Claims (6)

In laboratory instruments for containing or transferring a solvent or solution, Iii) a reference line for the determination of the molar or normal concentration is indicated, Ii) 0.5%, 1%, 2%, 3%, 4%, 5%, 6% of the concentration at the top of the reference line based on the molar or normal concentration determined by the size of the reference line; One is selected from a crowd of concentration intervals with decreasing concentrations of 7%, 8%, 9% and 10% or at the bottom of the reference line 0.5%, 1%, 2%, 3%, 4%, For measuring molar or normal concentrations in which one or more indicators are selected from the crowd at concentration intervals of increasing concentrations of 5%, 6%, 7%, 8%, 9% and 10%. Laboratory Instruments. The method of claim 1, The laboratory instrument is selected from the group consisting of beakers, flasks, measuring cylinders and pipettes. 3. The laboratory apparatus of claim 2, wherein the flask is a scalpel such as a round bottom flask or a wide bottom flask. The method of claim 1, The indication scale is an experimental instrument, characterized in that formed one at the top, one at the bottom. delete The method of claim 1, The concentration interval of 1% of the concentration decreases at the top of the reference indicator line based on the molar concentration or normal concentration determined by the size of the reference indicator line, and at the bottom of the reference indicator line at 1% of the concentration. Experimental instruments indicative of concentration intervals in which the concentration of s increases.

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