Which compound is used in hydrogen generators?

Which statement is not correct for ortho and para hydrogen?

Among the following,the correct statements are:
$I$. $LiH, BeH_2$ and $MgH_2$ are saline hydrides with significant covalent character.
$II$. Saline hydrides are volatile.
$III$. Electron-precise hydrides are Lewis bases.
$IV$. The formula for chromium hydride is $CrH$.
The correct option is:

The calorific value of producer gas is low because of:

Which of the following oxides cannot be reduced by hydrogen?

What is $X$ in the following reaction?
$NaH + B_2H_6 \xrightarrow{\text{Diethyl ether}} X$