Which of the following properties of $H_2$ (dihydrogen) gas is $NOT$ correct?

What is the ratio of dihydrogen gas to dinitrogen gas used in the production of ammonia gas by Haber's process?

The following reaction is an example of a:
$4 NH_{3}(g) + 5 O_{2}(g) \rightarrow 4 NO(g) + 6 H_{2}O(g)$
$(i)$ Displacement reaction
$(ii)$ Combination reaction
$(iii)$ Redox reaction
$(iv)$ Neutralisation reaction

What is the name of the apparatus used for the electrolysis of pure water?

Which of the following is(are) an endothermic process(es)?
$(i)$ Dilution of sulphuric acid
$(ii)$ Sublimation of dry ice
$(iii)$ Condensation of water vapours
$(iv)$ Evaporation of water

Crystals of copper sulphate are heated in a test tube for some time. What is the source of liquid droplets seen on the inner upper side of the test tube during the heating process?