it is true that the control is heated in an oven along with the other cups sitting in a tray. This is to drive off all the moisture. Then they are all placed together in a tray in a desiccator. I am pretty sure I would get the same results by using the control all by its lonesome.
tell me if this is the wrong way to think about it?
If you could weigh a constant mass of gas at temp 35 degrees then that same mass of gass would weigh less at 40 degrees because it has expanded and is trying to rise.
Why would this not work for a metal?
I don't know I am just confused...
the balance has sliding doors on it so the cup sits inside of an enclosed box. It only takes 10-20 seconds for me to get the cup out of the desiccator and onto the balance.
yes the control does change and you are correct to think it doesn't get put through any extraction process. it just sits there in the tray. It is only heated in the oven and cooled in a desiccator.
so basically, in order for me to get a weight within 0.0005g of its initial weight I have to...
the process for extraction doesn't really matter.
I initially weigh an empty metal cup that has been cooled in a desiccator after being removed from an oven. Later, I take the same cup which has had nothing added, dry it in an oven, cool it in a desiccator and weigh it again on a balance.
One of my jobs at work is to determine the amount of oil and grease present in wastewater samples. In the beginning of the procedure I usually take a tray of oil and grease cups out of a 125 degree oven and place it in a desiccator for roughly an hour before weighing on a balance. After...