The crucible must be cold before weighing because the heat from the crucible will warms the surrounding air
This is gibberish.
It reduces errors caused by variations in the weight of the crucible itself.Taring is accurately establishing the empty weight of the crucible, which can vary with contaminants, residue, or oxides. By repeatedly heating, cooling, and weighing the crucible, until there is only an acceptable variation between weighings, the actual weight of samples before and after incineration can be more precisely measured.
The crucible must be weighted at a constant temperature, generally 20 oC. During an analytical determination - for example - all the weighings must be made at the same temperature. Also a hot crucible has a negative influence on the balance.
A desiccator is used to cool a crucible in order to prevent the absorption of moisture during the cooling process so an accurate result can be obtained
There are a few reasons: Safety, so individual does not get burned; a hot crucible could damage the scale; hot crucible could alter the substance being weighed; a hot crucible as the heat is released into surrounding air, it causes convection air currents when using an electronic scale than measures to multiple decimal places can give a miss reading and give the individual a larger error percentage in their experiment.
The percent of water is determined by the loss is mass after heating the water vapor condensed on the crucible wall before heating.
the crucible might be hot hence it is handy
It reduces errors caused by variations in the weight of the crucible itself.Taring is accurately establishing the empty weight of the crucible, which can vary with contaminants, residue, or oxides. By repeatedly heating, cooling, and weighing the crucible, until there is only an acceptable variation between weighings, the actual weight of samples before and after incineration can be more precisely measured.
It reduces errors caused by variations in the weight of the crucible itself.Taring is accurately establishing the empty weight of the crucible, which can vary with contaminants, residue, or oxides. By repeatedly heating, cooling, and weighing the crucible, until there is only an acceptable variation between weighings, the actual weight of samples before and after incineration can be more precisely measured.
The reason you heat the test tube before weighing it is because of the residual moisture on the test tube itself. The weight of the glass itself will not change, but if there is moisture inside the tube, it could distort your readings. Therefore, you heat the test tube to evaporate any moisture remaining in the test tube to get an accurate weight measurement.
A desiccator is used to cool a crucible in order to prevent the absorption of moisture during the cooling process so an accurate result can be obtained
The crucible must be weighted at a constant temperature, generally 20 oC. During an analytical determination - for example - all the weighings must be made at the same temperature. Also a hot crucible has a negative influence on the balance.
Because fingerprints can add a considerable mass to the crucible when weighing it.
Crucible tongs are made up of aluminum that used for moving the crucibleswhen they are still hot to cool it down.
There are a few reasons: Safety, so individual does not get burned; a hot crucible could damage the scale; hot crucible could alter the substance being weighed; a hot crucible as the heat is released into surrounding air, it causes convection air currents when using an electronic scale than measures to multiple decimal places can give a miss reading and give the individual a larger error percentage in their experiment.
Heating a metal in a crucible can cause the metal to react with the surrounding gases. thus, when weighing the metal after heating, the mass increases because of the addition of the gaseous elements
A hot beaker warms the air around it, which causes it to rise. For very sensitive balances, the updraft produced can reduce the measured weight.
before then after