A pendulum clock loses 10.8 seconds a day when the temperature is \( 38^\circ C \) and gains 10.8 seconds a day when the temperature is \( 18^\circ C \). The coefficient of linear expansion of the metal of the pendulum clock is:
The correct order of boiling points of hydrogen halides is:
In a triangle \(ABC\), if
\[ (a - b)^2 \cos^2 \frac{C}{2} + (a + b)^2 \sin^2 \frac{C}{2} = a^2 + b^2, \]
then \( \cos A \) is:
Match the following substances with their respective equivalent weights:
The major product 'Y' in the given sequence of reactions is: