91Ó°ÊÓ

Both temporary and permanent hardness in water is removed by: (a) boiling (b) filtration (c) distillation (d) decantation

Hydrogen peroxide is not: (a) a reducing agent (b) an oxidising agent (c) a dehydrating agent (d) a bleaching agent

Hydrogen peroxide has a: (a) linear structure (b) closed chain structure (c) closed book type structure (d) half open book type structure

When \(50 \%\) solution of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) is electrolysed by passing a current of high density at low temperature the main products of electrolysis are: (a) oxygen and hydrogen (b) \(\mathrm{H}_{2}\) and peroxy disulphuric acid [ (c) \(\mathrm{H}_{2}\) and \(\mathrm{SO}_{2}\) (d) \(\mathrm{O}_{2}\) and peroxy disulphuric acid

Given colourless liquid will be determined whether it is water or not? (a) By smelling (b) By tasting 1 (c) By phenolphthalein (d) By adding a pinch of anhydrous \(\mathrm{CuSO}_{4}\)

Out of \(\mathrm{LiH}, \mathrm{MgH}_{2}\) and \(\mathrm{CuH}\) : (a) all are ionic hydrides (b) \(\mathrm{LiH}, \mathrm{MgH}_{2}\) are ionic and \(\mathrm{CuH}\) is covalent (c) all are covalent (d) LiH is ionic, \(\mathrm{MgH}_{2}\) and \(\mathrm{CuH}\) are intermediate

The hardness of water sample containing \(0.002\) mole of magnesium sulphate dissolved in a litre is expressed as: [P.E.T. (Kerala) 2007] (a) \(20 \mathrm{ppm}\) (b) \(200 \mathrm{ppm}\) (c) \(2000 \mathrm{ppm}\) (d) \(120 \mathrm{ppm}\) (e) 240 ppm