$26.$Ammonia synthesis gas is produced from natural gas by

Thermal cracking

Steam reforming

Partial oxidation

Hydrogenation

$27.$Ammonia synthesis reaction is

Exothermic

Endothermic

Autocatalytic

None of these

$28.$Ammonium nitrate $($a fertiliser$)$ is coated with limestone powder to

Increase its nitrogen content

Cut down its production cost

Avoid the risk of explosion

Add extra nutrient as fertiliser

$29.$Ammonium nitrate is

Having about $40\%$ N$4$

Not hygroscopic

Not prone to explosive thermal decomposition

Mixed with limestone powder to reduce its explosive nature before using it as a fertilizer