Q.Explain the following observations

Step 1 (a). An aerated water bottle contains dissolved CO$_2$ under pressure; kept underwater in summer, it stays cool, which (by Gay-Lussac's law, at the bottle's essentially fixed volume) keeps its internal pressure from rising as high as it would in the hot summer air -- reducing the risk of the bottle bursting.

Step 2 (b). A liquid ammonia bottle is cooled before its seal is opened because cooling lowers the vapour pressure of the ammonia trapped above the liquid, making the release, when the seal is broken, far gentler and safer than it would be at a higher (uncooled) pressure.

Step 3 (c). A tyre is inflated to slightly lower pressure in summer because the trapped air will itself heat up on a hot day and its pressure will rise (Gay-Lussac's law, constant volume) -- starting a little lower in summer avoids ending up dangerously over-pressurised once the tyre warms up. …

Work through each of the four scenarios, identifying whether it is primarily a Gay-Lussac's-law (fixed volume, pressure vs temperature) or Boyle's-law (fixed temperature, pres …

• Treating all four parts as the same kind of gas-law situation, rather than noticing (a)-(c) are constant-volume/temperature-vs-pressure cases while (d) is really a …