1.Hydrogen can be prepared with zinc by using: (i)acid (ii)alkali (iii)water give an equation in each case. Ans. Zn+2HCl9(dil)-->ZnCl2 + H2 (ii) Zn+2NaOH(conc.) -(boil)-> Na2ZnO2 + H2 (iii)Zn+H2O ->ZnO+H2 2.for lab prep. of hydrogen,give the following: a) material used b)method of collection c)chemical equation d)a fully labelled diagram Ans. a)material used : flask, cork, thistle funnel, delivery tube, trough, glass tube and jar, granulated zinc and dil. sulphuric acid. method of collection : Downward displacement of water. chemical equation: Z n ( s ) + H 2 S O 4 ( a q ) → Z n S O 4 ( a q ) + H 2 ( g ) A fully labelled diagram. 3 (a) Write the name of impurities present in hydrogen in lab preparation (b) how can you remove it Ans. HydrogenSulphide,SulphurDioxide, Oxides Of Nitrogen Phosphine(PH3),CarbonDioxide, Water Vapour are impurities in hydrogen b) i)silver nitrate remove PH3 and AsH3 ii)lead nitrate remove H2S iii) c
