======Use of Laboratory Balances======


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**Alternative titles:** Techniques for Accurate Weighing
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====Summary====                   
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====Procedure====  
  -Determine the level of accuracy needed and select the appropriate balance (analytical for high precision, top-loading for general use).  
  -Check that the balance is clean, dry, and at room temperature.  
  -Turn on the balance and press the tare button to reset it to zero.  
  -Place your container (such as a beaker, flask, or weighing bottle) on the balance and record its mass.  
  -Add your sample either by:  
    -Using the weighing by difference method (weigh container, remove a portion, reweigh, and calculate mass transferred).  
    -Using direct transfer into a tared container, ensuring no spillage or contamination.  
  -For analytical balances, always close the balance doors before taking a measurement.  
  -Record the mass to the proper number of significant figures according to the balance used.  
  -Clean up any spills immediately and return the balance to zero before leaving.



====Links==== 
Lab Balance Tutorial - frank deering: 
{{youtube>0DZOeKu_9Uc?}}\\


📄 Proper Use of Balances - Oliver Seely: [[https://chem.libretexts.org/Ancillary_Materials/Demos_Techniques_and_Experiments/General_Lab_Techniques/Proper_Use_of_Balances]]\\


====Variations====
  *Use weighing paper for top-loading balances (never for analytical balances).  
  *Seal and dry crucibles or samples in an oven before weighing to constant mass.  
  *Transfer solids using a spatula or pouring techniques, depending on the sample container.



====Safety Precautions====
  *Do not place chemicals directly on the balance pan.  
  *Always use dry, clean containers to prevent mass errors and damage.  
  *Avoid touching samples or containers with bare hands to prevent contamination.  
  *Handle glassware carefully to avoid breakage.  
  *Clean spills inside the balance enclosure immediately.




====Questions to Consider====
  *Why must balance doors be closed during weighing? (To prevent air currents from affecting the reading.)  
  *Why should warm objects not be weighed immediately? (They create convection currents and density differences that cause errors.)  
  *When should an analytical balance be used instead of a top-loading balance? (When four or more significant figures are required, such as for unknowns or primary standards.)  
  *What is the advantage of weighing by difference? (It minimizes exposure to air and provides precise measurements of transferred material.)