Problem 119 - General Chemistry

Question

Gallium metal can be melted by the heat of one's hand. Its melting point is \(29.8^{\circ} \mathrm{C}\). What is this temperature in kelvins? in degrees Fahrenheit?

Step-by-Step Solution

Answer

Ga's melting point is 302.95 K and 85.64°F.

Step 1: Convert Celsius to Kelvin

To convert from degrees Celsius to Kelvin, use the formula: \[ K = °C + 273.15 \] For gallium, \[ K = 29.8 + 273.15 = 302.95 \] Thus, the melting point of gallium in Kelvin is 302.95 K.

Step 2: Convert Celsius to Fahrenheit

To convert from degrees Celsius to degrees Fahrenheit, use the formula: \[ °F = °C \times \frac{9}{5} + 32 \] For gallium, \[ °F = 29.8 \times \frac{9}{5} + 32 = 85.64 \] Thus, the melting point of gallium in Fahrenheit is 85.64°F.

Key Concepts

Celsius to Kelvin

When converting temperatures from Celsius to Kelvin, you're transitioning from one scale to another that begins at absolute zero. To make this conversion, use the simple formula: \[ K = °C + 273.15 \] This equation adds a constant of 273.15 to the Celsius temperature since 0 Celsius is equivalent to 273.15 Kelvin.
- Kelvin is the SI unit of temperature and does not use the word "degree."- A temperature in Kelvin can never be negative.
For example, if you have a temperature of 29.8 degrees Celsius, like the melting point of gallium, you convert it to Kelvin by adding 273.15, resulting in 302.95 Kelvin.

Celsius to Fahrenheit

Converting Celsius to Fahrenheit involves moving to a temperature scale familiar to those in the United States. Use the formula: \[ °F = °C \times \frac{9}{5} + 32 \]
Here's a breakdown of the conversion:

• Multiply the Celsius temperature by \(\frac{9}{5}\).
• Add 32 to this result.

This method accounts for the difference in scale size between the two units.
For instance, with gallium’s melting point of 29.8 degrees Celsius, you'd multiply by \(\frac{9}{5}\) and then add 32. The converted temperature is 85.64 degrees Fahrenheit.
- The Fahrenheit scale uses 32 as the freezing point of water instead of 0, like Celsius.

melting point of gallium

Gallium is a fascinating element with a melting point of 29.8°C, making it so low that it can melt by just holding it in your hand. This unique property is due to the metallic bonds in gallium which require only a small amount of energy to break.
- Gallium’s melting point in other units can be computed as 302.95 Kelvin and 85.64 degrees Fahrenheit. - Its low melting point is useful in some electronic applications, like thermometers, where quick and easy melting and solidifying can be beneficial.
Additionally, gallium does not melt at room temperature, adhering instead to surfaces like your palm, making it a neat demonstration of phase change that can be explored in educational settings.