In the chemical reaction,
Cl2 + H2S → 2HCl + S.
The oxidation number of sulphur changes from
0 to 2
2 to 0
-2 to 0
-2 to -1
In the reaction,
3Mg + N2 → Mg3N2
magnesium is reduced
magnesium is oxidised
nitrogen is oxidised
None of the above
With the increase in atomic weights, melting points of the alkali metals
increase
decrease
remain constant
do not show definite trend
Alkali metals in each period have
smallest size
owest ionization potential
highest ionisation potential
highest electronegativity
Ferric ion forms a Prussian blue coloured precipitate due to formation of
K4[Fe(CN)6]
Fe4[Fe(CN)6]3
Fe(CNS)3
K3[Fe(CN)6]
The reactivity of the alkali metal sodium with water, is made use of
in drying of alcohols
in drying of benzene
in drying of organic amines
as a general drying agent
The bleaching action of the bleaching powder is due to the liberation of
chlorine
molecular oxygen
nascent oxygen
calcium carbonate
Al3+, Fe3+, Zn2+ and Ni2+ ions are present in an acidic solution. Excess of ammonium chloride solution followed by addition of ammonium hydroxide solution. The available precipitate will contain
Zn(OH)2 and Ni(OH)2
Al(OH)2 and Fe(OH)3
Zn(OH)2 and Al(OH)3
Ni(OH)2 and Fe(OH)3
B.
Al(OH)2 and Fe(OH)3
The increases concentration of NH ions, furnished by the strong electrolyte, NH4Cl, suppresses the ionisation of the weak electrolyte, NH4OH. So, the concentration of OH- ions becomes so low that the product of M3+ ions and the OH- ions exceed the solubility product of hydroxides of Fe and Al. So, they precipitate out. The values of solubility products of hydroxides of Ni and Zn being very high, not exceeded with low concentration of OH- ions.