Question

Explain the following observations: a. More sugar dissolves in hot tea than in iced tea. b. Champagne in a warm room goes flat. c. A warm can of soda has more spray when opened than a cold one.

Short answer

a. Higher temperature increases sugar solubility. b. Higher temperature decreases gas solubility. c. Higher temperature increases gas pressure, leading to more spray.

Step-by-step solution

- Understand solubility and temperature

For part (a), recognize that solubility of solids in liquids generally increases with temperature. Higher temperatures provide more kinetic energy, which helps dissolve more sugar in hot tea compared to iced tea.

- Relate gas solubility to temperature

For part (b), understand that the solubility of gases in liquids decreases as the temperature increases. In a warm room, the carbon dioxide in champagne is less soluble, so it escapes more easily, causing the champagne to go flat.

- Explain pressure and temperature effects on gas release

For part (c), consider that a warm soda can have higher internal pressure due to increased temperature. When opened, this higher pressure results in a more vigorous release of carbon dioxide, causing more spray compared to a cold can.

Key concepts

Solubility of Solids

Solubility of solids refers to how much of a solid (solute) can dissolve in a liquid (solvent) to form a solution. It is influenced by various factors, with temperature being one of the primary ones. As temperature increases, the kinetic energy of the molecules rises. This increased energy helps break the intermolecular bonds in the solid, allowing more particles to diffuse into the solvent.
For example, more sugar dissolves in hot tea than in iced tea because the higher temperature of the hot tea provides the energy needed for the sugar molecules to separate and integrate into the liquid. Conversely, in iced tea, the colder temperature keeps the kinetic energy low, resulting in less sugar solubility.

Solubility of Gases

Solubility of gases in liquids behaves differently than that of solids. Generally, gases become less soluble as the temperature increases. This is due to the higher kinetic energy at elevated temperatures, making gas molecules more likely to escape from the liquid into the air.
For instance, champagne stored in a warm room loses its fizz because the carbon dioxide gas becomes less soluble at higher temperatures and escapes quickly. This is why champagne goes flat in warmer conditions. The solubility of gases, such as CO₂ in the liquid, is much lower in warm conditions compared to cold ones.

Temperature Effects on Solubility

Temperature plays a crucial role in determining the solubility of both solids and gases in liquids. For solids, increased temperature usually means higher solubility. This is due to the added energy that breaks down the solid's molecules and helps integrate them into the solvent.
On the other hand, gases behave oppositely; a rise in temperature generally leads to decreased solubility. Higher temperatures add energy to gas molecules, making them more likely to escape into the atmosphere.
Understanding these temperature effects can explain why more sugar dissolves in hot tea and why champagne goes flat in a warm room.

Pressure and Gas Release

Pressure also affects the solubility of gases in liquids. Higher pressures increase gas solubility in liquids by forcing more gas molecules into the solvent. When a container is opened, the pressure quickly drops, allowing the gas to escape.
In the case of a soda can, a warm can has a higher internal pressure due to the increased temperature. This elevated pressure increases the presence of CO₂ gas dissolved in the soda. Upon opening, the rapid pressure release causes the gas to escape energetically, resulting in more spray.
Understanding the relationship between temperature and pressure helps explain why a warm can of soda sprays more than a cold one.