I’m doing a chemistry lab and this was one of the questions in my review, and the package says to never weigh a hot object but it doesn’t say why
handling hot objects is simply not as safe as handling room temperature objects
also, hot objects will radiate heat in the form of convection currents, making small changes (instabilities) in your readings
When the air is heated, the energy from the heat causes the air molecules to move faster and separate
This means that the mass is less dense than if the object were cold (where the molecules are close and compact)
Source(s): http://wwwsciencenetlinkscom/lessons_printablec
this may be incorrect technique, but I wouldn’t imagine the stiffness in expelling the heat pushing down on the textile could be great even if balanced against moisture absorbed from the air once the textile has cooled
A hot object will heat the air around it
it As hot air rises, the hot object will create a small air current around it
This air current will be detected by the scale, giving you an incorrect reading
Because convection currents cause the readings to become unstable
This effect can produce significant errors even when the object is only a few degrees above room temperature
Convection currents from the hot object cause the readings to become unstable
Source(s): http://wwwowlnetriceedu/~chem122/equipmenthtml
From what I remember it was because the cooling causes air currents which would affect the accuracy of the measurement
Convection would apply force to the weighing surface
Any air current would affect the reading
A hot object will expand and possibly weigh more or less (depending on the material and laboratory conditions) as it cools
Next time you’re in the lab go ahead and put a hot substance on the scales
Watch as it cools – the weight will decrease
Because it is hot, it may have a different mass than when you originally weighed it at room temperature
you don’t weigh hot objects in a sensitive chemistry lab scale because the heat causes convective air currents, and the air movement upsets the balance
you know air movement is a problem if the scale has windows you close to take a measurement
Why would you never weigh a hot object?
When weighing small things I tend to like to be able to handle them with gloves – so it helps if the object is warmer than the dew point (so condensation doesn’t change the weight of the object) and colder than say 45 degrees C
But I’ve often *had* to weigh hot items (straight from the oven) to minimize the absorption of water vapor
this means that the mass is much less dense than if the object is replaced to cool (the place where the molecules are close and compact)
All objects will have the same mass regardless of their temperature
Table of contents1 What happens if you weigh something hot?2 Why should hot objects not be placed on the pan of a scale?3 Why is it necessary to heat the crucible before weighing?4 Is cold water heavier than hot?5 Is it bad to leave weight on a scale ?6 Why shouldn’t hot objects be weighed without first cooling to room temperature?7 Is it safe to weigh a hot object?8 What happens to the pan when an object is hot?
What happens if you weigh something hot?
If you have perfectly identical objects that have the exact same weight when they are at the same temperature, then when an object is heated it will weigh more
Why shouldn’t hot objects be placed on the forehead to get a balance?
Does temperature affect weight scale?
The slightest change in room temperature can cause noticeable changes in the weight of the sample
Why is it necessary to heat the crucible before weighing?
You need to let the crucible cool before you measure it because the heat from the crucible heats the surrounding air that rises, then that air cools and falls
This rise and fall of ambient air is called a convection current and will give you an erratic reading that rises and falls
Is cold water heavier than hot?
Like air, water expands as it gets warmer and becomes less dense as a result
Water is densest at temperatures close to freezing
When water freezes, however, it expands and becomes less dense
F) and hot water are compared, cold water weighs more than hot water
Do we weigh more when it’s hot?
Is it bad to leave weight on a scale?
Placing excess weight on a scale will permanently damage its sensitive measuring components
Why should hot objects not be weighed without first cooling to room temperature?
Air rises when heated by a hot sample
This creates convection currents that make the displayed mass unreliable
Wait until the sample has cooled to room temperature before weighing it
3) Do not weigh hot or cold objects on the scale
3) Do not weigh hot or cold objects on the scale
Hot objects falsely give lower values due to air buoyancy, while cold objects give higher values due to condensation of water vapor
Is it safe to weigh a hot object?
At first it is not safe to handle hot objects
Recognizing this, objects should also not be weighed hot because hot objects give off convection currents that will affect readings on precision scales quite noticeably
It is a misconception that heat will actually affect mass
What happens to the scale pan when an object is hot?
A warm or hot object will create a convection current in the air around the weighing pan
A warm or hot object will create a convection current in the air around the weighing pan
This fluctuating force reduces the air pressure on the balance pan and can make it difficult to get a stable reading
This fluctuating force reduces the air pressure on the balance pan and can make it difficult to get a stable reading
Q: Why should you never weigh objects while they are still hot?
When does heat flow from a hot object to a colder object?
On which object would you weigh the least?
https://wwwyoutubecom/watch?v=LWDgdPKkVnU