$$2.7 \mathrm{~kg}$$ of each of water and acetic acid are mixed. The freezing point of the solution will be $$-x^{\circ} \mathrm{C}$$. Consider the acetic acid does not dimerise in water, nor dissociates in water. $$x=$$ ________ (nearest integer)

[Given: Molar mass of water $$=18 \mathrm{~g} \mathrm{~mol}^{-1}$$, acetic acid $$=60 \mathrm{~g} \mathrm{~mol}^{-1}$$

$${ }^{\mathrm{K}_{\mathrm{f}}} \mathrm{H}_2 \mathrm{O}: 1.86 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$

$$\mathrm{K}_{\mathrm{f}}$$ acetic acid: $$3.90 \mathrm{~K} \mathrm{~kg} \mathrm{~mol}^{-1}$$

freezing point: $$\mathrm{H}_2 \mathrm{O}=273 \mathrm{~K}$$, acetic acid $$=290 \mathrm{~K}$$]

Consider the following reaction, the rate expression of which is given below

$$\begin{aligned} & \mathrm{A}+\mathrm{B} \rightarrow \mathrm{C} \\ & \text { rate }=\mathrm{k}[\mathrm{A}]^{1 / 2}[\mathrm{~B}]^{1 / 2} \end{aligned}$$

The reaction is initiated by taking $$1 \mathrm{~M}$$ concentration of $$\mathrm{A}$$ and $$\mathrm{B}$$ each. If the rate constant $$(\mathrm{k})$$ is $$4.6 \times 10^{-2} \mathrm{~s}^{-1}$$, then the time taken for $$\mathrm{A}$$ to become $$0.1 \mathrm{~M}$$ is _________ sec. (nearest integer)

Three moles of an ideal gas are compressed isothermally from $$60 \mathrm{~L}$$ to $$20 \mathrm{~L}$$ using constant pressure of $$5 \mathrm{~atm}$$. Heat exchange $$\mathrm{Q}$$ for the compression is - _________ Lit. atm.

Vanillin compound obtained from vanilla beans, has total sum of oxygen atoms and $$\pi$$ electrons is __________.