For which reaction change of entropy will be positive?
H2(g) + I2(g) 2HI (g)
HCl (g) + NH3 (g) NH4Cl (s)
NH4NO3 (s) N2O (g) + 2H2O (g)
MgO(s) + H2(g) Mg(s) + H2O(l)
Which of the following acids has the smallest dissociation constant?
CH3CHFCOOH
FCH2CH2COOH
BrCH2CH2COOH
CH3CHBrCOOH
Which one of the following processes is used for the manufacture of calcium?
Reduction of CaO with carbon
Reduction of CaO with hydrogen
Electrolysis of a mixture of anhydrous CaCl2 and KCl
Electrolysis of molten Ca(OH)2
Fe(OH)3 can be separated from Al(OH)3 by the addition of
NaCl solution
dil. HCl solution
NaOH solution
NH4Cl and NH4OH
C.
NaOH solution
Fe3+ and Al3+ both belongs to group IIIrd of inorganic analysis and both are precipitated as their hydroxides on adding group reagent, i.e. NH4OH in presence of NH4Cl.
Fe3+ + 3OH- → Fe(OH)3
Al3+ + 3OH- → Al(OH)3
Precipitate of Al(OH)3 is soluble in NaOH solution. Hence, Fe(OH)3 and Al(OH)3 are seperated by using NaOH solution.
Select the incorrect statement among the following:
O3 is used as germicide for purification of air
In O3, O-O bond length is identical with that of molecular oxygen
O3 molecule is angular in shape.
O3 is an oxidising agent
The brown complex obtained in the detection of nitrate radical is formulated as [Fe(H2O)5NO]SO4. What is the oxidation number of Fe in this complex?
+1
+2
+3
0
1 mole of methyl amine on reaction with nitrous acid gives at NTP
1.0 L of nitrogen
22.4 L of nitrogen
11.2 L of nitrogen
5.6 L of nitrogen