Question

Given below are two statements :
Statement I : Gallium is used in the manufacturing of thermometers.
Statement II : A thermometer containing gallium is useful for measuring the freezing point (256 K) of brine solution.
In the light of the above statement, choose the correct answer from the options given below :

• A. Both Statement I and Statement II are false
• B. Statement I is false but Statement II is true.
• C. Both Statement I and Statement II are true.
• D. Statement I is true but Statement II is false.

Answer 1

The Correct Option is D

To determine the correct answer, let's analyze the given statements:

1. Statement I: Gallium is used in the manufacturing of thermometers.
   • Gallium is indeed used in the manufacturing of thermometers. This is because gallium has a low melting point of about 29.76°C, which is close to room temperature. It can exist as a liquid at slightly above room temperature, making it useful in thermometers.
2. Statement II: A thermometer containing gallium is useful for measuring the freezing point (256 K) of brine solution.
   • The freezing point of brine solution is approximately -18°C, which corresponds to 255 K (or 256 K when rounded). Gallium, with a melting point of approximately 29.76 °C (or around 303 K), would be solid at this temperature. Therefore, a gallium thermometer cannot measure temperatures as low as 256 K since gallium would be in a solid state. Therefore, this statement is incorrect.

Based on the analysis above, the correct interpretation is:

• Statement I is true but Statement II is false.

Thus, the answer is: Statement I is true but Statement II is false.

Answer 2

• Statement I: True. Gallium is used in manufacturing thermometers due to its wide liquid range.
• Statement II: False. Gallium is used to measure high temperatures, not low temperatures like 256 K (freezing point of brine).