By what factor does the average velocity of a gaseous molecule increase when the temperature (in Kelvin) is doubled?

Which of the following compounds is not chiral?

Let $A = \{x_1, x_2, x_3, x_4\}$ and $B = \{y_1, y_2, y_3, y_4\}$. $A$ function $f: A \to B$ is defined. The number of one-one functions such that $f(x_i) \neq y_i$ for $i = 1, 2, 3, 4$ is equal to:

The number of points in $(-\infty, \infty)$ for which $x^2 - x \sin x - \cos x = 0$ is

If $f(x)=(\cos x)(\cos 2 x) \ldots(\cos n x)$,then $f^{\prime}(x)+\sum_{r=1}^n(r \tan r x) f(x)$ is equal to

Which of the following pairs is incorrectly matched?