The mercury manometer shown in the figure (Figure 1) is attached to a gas cell. The mercury height h is 120 mm when the cell is placed in an ice-water mixture. The mercury height drops to 30 mm when the device is carried into an industrial freezer.
Hint: The right tube of the manometer is much narrower than the left tube. What reasonable assumption can you make about the gas volume?
What is the freezer temperature?