The mass of a non-volatile, non-electrolyte solute (molar mass = 50 g mol^-1 ) needed to be dissolved in 114 g octane to reduce its vapour pressure to 75%, is :

The major product of the following reaction is :

For standardizing NaOH solution, which of the following is used as a primary standard ?

If the function f defined as

$$f\left( x \right) = {1 \over x} - {{k - 1} \over {{e^{2x}} - 1}},x \ne 0,$$ is continuous at

x = 0, then the ordered pair (k, f(0)) is equal to :