Write the rules of weighing
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Answer:
Some general rules for the weighing:
Never handle objects with your fingers to weigh. ...
Weigh at room temperature, thus avoiding currents of air convection.
Never place chemicals directly on the pan, but weigh them in a vessel (weighing bottle, weighingdish) or on powder paper.
Factors affecting weighing accuracy can have a negative impact on the overall results of an analysis, so it is critical to be aware of the rules that must be followed when working with laboratory balances.
Weighing is one of the most common, yet critical and time-consuming, tasks performed in the laboratory; thus, weighing correctly is essential.
IMPORTANT WEIGHING RULES:
1) Do not weigh objects with your bare hands. Tongs, paper towels, or gloves should be used. Because there are no gloves available, you will handle objects with paper towels.
2) Never weigh chemicals directly on the balance pan; instead, use vessels, weighing paper, or filter paper.
3) Do not use the balance to weigh hot or cold objects. Hot objects will give falsely low readings due to air buoyancy, whereas cold objects will give falsely high readings due to water vapor condensation.
4) Never spill chemicals inside the analytical balance enclosure. If you spill chemicals on the top loading balance, clean it as soon as possible. Maintain the cleanliness of the weighing chamber and weighing pan.
5) Avoid overloading the balance. The analytical balance's normal maximum capacity is 110 g.
6) Maintain balance at all times.
7) Make sure the pan is clean before using the balance. If it's filthy, notify your instructor. Then, using a special brush, clean the pan.
8) Check that the bubble in the Level Indicator is centered and the balance is set to "OFF". Your instructor may need to adjust the Leveling Feet.
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