Ensuring quality data collection is absolutely vital for the success of any science experiment, especially chemistry. Lab equipment such as Erlenmeyer flasks, test tubes, scientific balances, and beakers hold chemical reagents and the product of major reactions. Because the reactants and products in a chemical reaction must be carefully weighed and balanced for later analysis as well as the fact that certain reactions are difficult to instigate and maintain keeping glassware and other laboratory instruments free of contaminants is essential. Proper care of science lab equipment, especially chemistry lab equipment, is an essential skill for any modern day physical scientist.

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The most basic essential step to ensure that lab equipment is free of contaminants is to rinse any item used, whether before or after the beginning of an experiment, with deionized water. Using DI water to clean chemistry lab equipment is important because it is free of electric charge and has a relatively neutral pH. Water that is not DI that clings to the side of glassware will likely alter the pH of added solutions and introduce systematic error into later calculations. Any lab instruments that have been rinsed should be carefully dried using a towel that will not shed or leave any other residue - just remove the excess water from the instrument.

Science laboratory equipment is broken all too rainin its pipette tips often, but worse is when it is handled roughly or stored improperly and develops hidden cracks or chemical films. Many chemistry experiments require the use of strong acids and bases that must be contained in glassware. If they are exposed to skin they can cause serious burns. Glassware that has developed hidden cracks is prone to breaking when filled with a solution or bumped in the course of running an experiment and this breakage can lead to dangerous compounds spilling and splashing onto exposed skin. Science lab equipment improperly cleaned or stored can also be contaminated with chemicals that will undergo unwanted side reactions during an experiment, throwing off the validity of any results obtained.

Proper storage and maintenance of laboratory instruments is of utmost importance and fairly simple. When not in use, store all glassware and instruments in a sturdy closed cabinet. When handling them, use firm but gentle grips and move slowly and deliberately. Clean before and after experiments by rinsing with deionized water. And of course use the instrument that is best for the job. Trying to pour liquid into a buret without a funnel can lead to awkward movements, spilled chemicals, and broken laboratory instruments.

The pipette, the most commonly used equipment in laboratories for extracting the samples. It is mainly used for transferring liquids or semi-solids on laboratories. It's really interesting to know the working and internal mechanism of pipettes.

The pipette should be adjusted so that the dispensed volume will be within the required specifications. The pipettes can be mainly classified into two Air Displacement Pipettes and Positive Displacement Pipettes.

Air Displacement Pipettes - These types are called as air displacement pipettes because a certain volume of air remains between the piston and the liquid. These are only used for general purpose with aqueous solutions.

• There is a piston inside the pipette which will be moved to appropriate position when the volume is set.

• Piston will expel the same volume of air as indicated on the volume setting when the operating button is pressed.

• The operating button will be released after immersing the tip into the liquid, which will create a partial vacuum and the specified volume of liquid is aspirated into the tip.

• When the operating button is pressed to the first stop again, the air dispenses the liquid. To empty the tip completely the operating button is pressed to the second stop.

There is lot of factors like temperature, density and altitude which should be taken care otherwise it may seriously affect the accuracy of these air displacement pipettes.

Positive Displacement Pipettes - It is mainly used for high viscosity and volatile liquids. The specialty of these pipettes is that the piston will be in direct contact with the liquid. The tip of it contains a disposable plunger just like a syringe, which will displace the fluid without any errors. These types are the most accurate type of pipette but the disadvantage of this one is it's highly expensive, so this not used for general purposes.

There is lot of points to be remembered while using a pipette. First of all daily wipe the pipette with 70% ethanol so that there won't be dirt on the pipette. Now check whether the volume is in specified range. While holding the pipette the "grippy finger rest" should rest on the index finger. To get the maximum accuracy the pipette, tip and liquid should be kept at the same temperature. Its always better to use high quality tips which is made from contamination-free polypropylene for the pipette, so that the tip will ensure maximum accuracy. The metrological characteristics of the tips will change after each time of use so it should be cleaned after use. Its better to pre -rinse the tip three to four times with the liquid to be used. It will definitely increase the accuracy especially when using positive displacement tips. Don't turn the pipette on its side when there is liquid in the tip, liquid must go to the interior and contaminate it. Always try to store the pipettes on stands in upright position when not in use. If used daily it is recommended to check the calibration in three - month interval. Always follow the instructions of recalibration.