Question

Indicate the physical state (solid, liquid, or gas) for mercury given its melting point \(\left(-40{ }^{\circ} \mathrm{C}\right)\) and boiling point \(\left(357{ }^{\circ} \mathrm{C}\right)\) under the following conditions: (a) \(\mathrm{Hg}\) in ice water (b) \(\mathrm{Hg}\) in boiling water

Short answer

(a) Liquid, (b) Liquid

Step-by-step solution

Understand Mercury's Melting and Boiling Points

The melting point of mercury is \(-40^{\circ} \mathrm{C}\), which means it will be a liquid above this temperature and a solid below it. The boiling point is \(357^{\circ} \mathrm{C}\), so mercury will be a gas above this temperature and a liquid below it.

Analyze Condition (a) Mercury in Ice Water

Ice water is typically at \(0^{\circ} \mathrm{C}\). Since \(0^{\circ} \mathrm{C}\) is above mercury's melting point \((-40^{\circ} \mathrm{C})\) but below its boiling point \((357^{\circ} \mathrm{C})\), mercury will be in its liquid state in ice water.

Examine Condition (b) Mercury in Boiling Water

Boiling water has a temperature of \(100^{\circ} \mathrm{C}\). Since \(100^{\circ} \mathrm{C}\) is above mercury's melting point \((-40^{\circ} \mathrm{C})\) but below its boiling point \((357^{\circ} \mathrm{C})\), mercury will still be in its liquid state in boiling water.

Key concepts

Melting Point

The melting point of a substance is the specific temperature at which it transitions from a solid to a liquid state. For mercury, this temperature is \(-40^{\circ} \text{C}\), which is rather unique when compared to many other metals. Metals typically have much higher melting points. When mercury reaches this temperature, it transitions from a solid form to a liquid one, known as melting.

• Below \(-40^{\circ} \text{C}\), mercury is solid.
• At \(-40^{\circ} \text{C}\), it begins to turn into a liquid.
• Once above its melting point, mercury remains in the liquid state until it reaches its boiling point.

This quality makes mercury unique and suitable for specific applications like thermometers, where it stays liquid in typical temperature conditions.

Boiling Point

The boiling point of mercury is significant at \(357^{\circ} \text{C}\). This is the temperature where mercury undergoes a transition from a liquid to a gas. A boiling point represents the temperature at which a liquid's vapor pressure equals the surrounding pressure, triggering a phase change.

• Below \(357^{\circ} \text{C}\), mercury is in its liquid state.
• At \(357^{\circ} \text{C}\), the change from liquid to gas begins.
• Above this temperature, mercury exists as a gas.

Mercury's significant boiling point highlights why it remains a liquid under a wide range of conditions, perfect for use in scientific instruments and temperature control systems.

Mercury

Mercury is a fascinating element, with unique properties that distinguish it from most other metals. At room temperature, mercury is a liquid, unlike most metals which are solid. This is due to its low melting point of \(-40^{\circ} \text{C}\) and relatively high boiling point of \(357^{\circ} \text{C}\).
Understanding the states of mercury:

• As a solid, mercury can be seen below its melting point.
• In its liquid state, which is the most common, mercury appears silvery and metallic.
• Once it's heated beyond its boiling point, it turns into a vapor.

Mercury's unique place on the periodic table, often found in thermometers and various scientific apparatus, underscores its versatility and importance. It’s essential when studying states of matter to grasp these transition points thoroughly for understanding material behaviors.