Answer
$-246C^{\circ}$
Work Step by Step
We can determine the required temperature of hydrogen molecules as follows:
$T_h=T_n\frac{M_h}{M_n}$
We plug in the known values to obtain:
$T_h=(100+273)(\frac{2}{28})$
This simplifies to:
$T_h=27K=-246C^{\circ}$
