If you're asking if the volume of a volumetric flask made out of borosilicate glass changes after autoclaving, I'm in big trouble if it does. I've been autoclaving my flasks for 25+ years. If you're trying to be precise when making your solutions, the more important thing (in my opinion) is to make sure all the components of your solution, including water, are at room temperature (technically 20 degrees C) when you make the solution up.
Gordon L Warren sir,
I've seen markings on borosilicate volumetric flasks like: 1L (+/-)0.01L (say at 27 C). Will not the 1L mark shift at high temperature since there remains chance of expansion of the flasks?
The +/- number on the flask refers to the accuracy with which the line is drawn on the flask. For Class A (also called Class 1 or USP) flasks, the line is more accurately drawn than on Class B flasks. Yes, if the flask is hot when you make up your solution, the concentrations of your solutes will be inaccurate. That is why I recommended that you ensure that all components of your solution, including your flask, are at room temperature when you make up the solution.
Check the weight of pouring water at 20 deg C. Refer volume tables.
What you need to do is making sure that the flask is at the temperature at which it is rated, and this is usually 20 °C. (Let's call 20 °C as it is, not "room temperature" because room temperature varies around the world).
Secondly, you might need to calibrate your flasks (and all your measuring instruments for that matter) to be at least 95 % sure that it is measuring what it says. For this, you need a competent calibration laboratory.
I wonder if the cubic thermal expansion of glass is relevant, so the temperature value at filling: e.g., for Corning 790 glass is 2.4 ppm/°C, thus, with the tolerance of the marking of 1% you are reporting, I think that you can safely skip this issue as an uncertainty component.
The calibration of the flask should be considered as a fully distinct issue. However, for an uncertainty of 1%, I do not think that is worth any other calibration certificate. Unless you need a higher precision: but in this case I wonder if the accuracy of the mark allows you for a better precision ( e.g., if you mistake by 1 mm the position of your filling level, which fraction of a cc would this correspond?)
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