What is the product obtained from the dehydration of glycerol?

If $\alpha+\beta=-2$ and $\alpha^3+\beta^3=-56$,then the quadratic equation whose roots are $\alpha$ and $\beta$ is

The product of the given reaction is:

Match the items given in Column $I$ with those in Column $II$ and select the correct option given below:

Column $I$	Column $II$
$(a)$ Tidal volume	$(i)$ $2500 - 3000 \ mL$
$(b)$ Inspiratory Reserve volume	$(ii)$ $1100 - 1200 \ mL$
$(c)$ Expiratory Reserve volume	$(iii)$ $500 - 550 \ mL$
$(d)$ Residual volume	$(iv)$ $1000 - 1100 \ mL$

$20 \text{ mL}$ of $0.1 \text{ M}$ acetic acid is mixed with $50 \text{ mL}$ of potassium acetate. $K_a$ of acetic acid $= 1.8 \times 10^{-5}$ at $27^\circ \text{C}$. Calculate the concentration of potassium acetate if the $pH$ of the mixture is $4.8$. (in $\text{ M}$)

The threshold wavelength of tungsten is $2300 \, \mathring{A}$. If ultraviolet light of wavelength $1800 \, \mathring{A}$ is incident on it,then the maximum kinetic energy of photoelectrons would be about ............ $eV$.