If the freezing point of an aqueous solution of salt $MX_4$ $(\alpha = 90\%)$ is $-3\,^{\circ}C$,then its boiling point will be ......... $^{\circ}C$. (Assume it is $100\%$ ionized at boiling temperature and $k_f = 1.86\,K\,kg\,mol^{-1}, k_b = 0.52\,K\,kg\,mol^{-1}$)

$A$ block of mass $m$ lying on a rough horizontal plane is acted upon by a horizontal force $P$ and another force $Q$ inclined at an angle $\theta$ to the vertical. The minimum value of the coefficient of friction between the block and the surface for which the block will remain in equilibrium is:

The major product $A$ is:

Assertion $A$: An astronaut inside a massive spaceship orbiting around the Earth will experience a finite but small gravitational force.
Reason $R$: The centripetal force necessary to keep the spaceship in orbit around the Earth is provided by the gravitational force between the Earth and the spaceship.

One line of the pair of lines $x^2+xy-2y^2=0$ is perpendicular to one line of the pair of lines $3y^2-5xy-2x^2=0$. If the combined equation of the two lines other than those two perpendicular lines is $ax^2+2hxy+by^2=0$,then $a+2h+b=$

Anhydrous $Na_2CO_3$ is also known as