Hydrides, Water and its Properties - Free MCQ Practice Test with solutions,

The order of reactivity of halogens with hydrogen is that Fluorine’s reactivity is greater than that of chlorine and chlorine’s reactivity is greater than that of bromine and bromine’s reactivity is greater than that of Iodine.

At 673 Kelvin and 200 atmospheric pressure, one mole of nitrogen combines with three moles of hydrogen in presence of iron and molybdenum in order to form 2 moles of ammonia and the enthalpy change is 92.6 KJ per Mol, the enthalpy here change is negative.

and belong to -block and since the electronegativity difference between these elements and is very less, they form covalent hydrides.

When one mole of heavy water reacts with one mole of sodium, it results in the formation of 1 mole of sodium deuteroxide and half a mole of deuterium it is represented chemically as 1D₂O + 1Na → 1NaOD + 1/2D₂.

Lime is added to hard water to remove temporary hardness. (Clark's method)

(a) Heavy water is injurous to human beings, plants and animals since it slows down the rates of reactions occuring in them.
(b) Heavy water reacts with aluminium carbide forming deuteromethane.

(c) In interstitial hydrates or deuterates, water molecules are present in interstitial sites or voids in the crystal lattice. e.g., and similarly are interstitial compounds.

The temporary hardness of water is due to the presence of bicarbonates of and . This may be removed by Clark's process. In this process, addition of calculated quantity of lime causes precipitation of  CaCO₃ as