Question

Gallium (, ) is a metalloid obtained from its salts during the smelting of ores of other elements, like Zinc. has broad applicability in the electronics industry. It is also used as a safe replacement for mercury in thermometers as it melts at and has a heat of fusion of . What is the entropy change of of gallium in as it melts when placed on a surface at

Answer 1

The given question is incomplete. The complete question is:

Gallium (Ga, 69.723 g/mol) is a metalloid obtained from its salts during the smelting of ores of other elements, like Zinc. has broad applicability in the electronics industry. It is also used as a safe replacement for mercury in thermometers as it melts at 29.8 °C and has a heat of fusion of 5.59 kJ/mol. What is the entropy change of 22 g of gallium in J/K as it melts when placed on a surface at 29.8°C?

Answer: The entropy change of of gallium in as it melts when placed on a surface at  is 5.81 J/K

Explanation:

Latent heat of fusion is the amount of heat required to convert 1 mole of solid to liquid at atmospheric pressure.

Amount of heat required to melt 1 mole of Ga = 5.59 kJ

Mass of Ga given = 22 gram

Heat required to melt 69.723 g of Ga = 5.59 kJ

Thus Heat required to melt 22 g of Ga = $\frac{5.59kJ}{69.723}\times 22=1.76kJ$

Temperature = $29.8^0C=(273+29.8)kJ=302.8kJ$

Now entropy change = $\frac{\text {heat of fusion}}{\text {temperature in K}}=\frac{1.76kJ}{302.8K}=0.00581kJ/mol=5.81J/K$

Thus the entropy change of of gallium in as it melts when placed on a surface at $29.8^0C$ is 5.81 J/K