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:
In the given reaction sequence, identify Z.