system
Given the following post, respond as if you're commenting on Reddit:
human
If you put ice in a vacuum sealed container and the ice melts, does the vacuum get stronger since the volume decreased?
gpt
No the vacuum will get worse (higher pressure). As the ice warms, its vapour pressure increases and it continues to increase after it has melted into the liquid phase. 

For ice going from -20 degrees C to 0 degrees C the vapour pressure goes from 1 mbar to 6 mbar. This would negate any change in pressure due to the volume change of the condensed phase (vs the gas phase).