How, when other terms are constant, $(R \cdot M . S) \propto \sqrt{T}$.

$\frac{(R \cdot M \cdot S)_{1}}{(R \cdot M \cdot S)_{2}}=\frac{\sqrt{T_{1}}}{\sqrt{T_{2}}}$

Here, $(R \cdot M \cdot S)_{2}=2 \cdot(R \cdot M \cdot S)_{1}$

$T_{1} =100^{\circ} C =(100+273) K =373 \; K$

$\therefore \frac{(R \cdot M \cdot S)_{1}}{2 \cdot(R \cdot M \cdot S)} =\frac{\sqrt{373}}{\sqrt{T_{2}}}$

$\sqrt{T_{2}} =2 \cdot \sqrt{373}$

$T_{2} =1492 \; K$ [squaring both sides]

Convert into celcius.,

$T_{2}=(1492-273)^{\circ} C =1219^{\circ} C$