The number of electrons that are involved in the reduction of permanganate to manganese (II) salt, manganate and manganese dioxide respectively are
5, 1, 3
5, 3, 1
2, 7, 1
5, 2, 3
A.
5, 1, 3
Permanganate ion is MnO.
(i) Conversion of permanganate into manganese (II) salt.
MnO → Mn2+
x + (-2)4 = -1 + 2
x = + 7
Change in number of electrons = 7 - 2 = 5
(ii) Conversion of permanganate into manganate.
MnO → MnO
x + (-2)4 = -1 x +(-2)4 = -2
x = +7 x = +6
Change in number of electron = 7 - 6 = 1
(iii) Conversion of permangante into manganese dioxide (MnO2)
MnO → Mn2+O2
x + (-2)4 = -1 x+(-2)2 = 0
x = +7 x - 4 = 0
x = +4
Change in number of electrons = 7 - 4 = 3
Thus, the number of electrons involved in the given reduction processes are respectively 5, 1 and 3.
The calculated magnetic moment of a divalent ion of an atom with atomic number 24 in aqueus solution is
4.90 BM
5.92 BM
3.87 BM
2.84 BM
The entropy of vaporisation of a liquid is 58 JK-1 mol-1. If 100 g of its vapour condenses at its boiling point of 123° C, the value of entropy change for the process is
-100 JK-1
100 JK-1
-123 JK-1
123 JK-1
The values of limiting ionic conductance of H+ and HCOO- ions are respectively 347 and 53S cm2 mol-1, the dissociation constant of methanoic acid at 298 K is
2.5 × 10-4
2 × 10-5
2.5 × 10-5
1.5 × 10-4
In a closed cylinder of capacity 24.6 L, the following reaction occurs at 27°C.
A2 (s) B2 (s) + 2C (g)
At equilibrium, 1 gm of B2 (s) (molar mass = 50 g mol-1) is present. The equilibrium constant Kp for the equilibrium in atm2 unit is
(R = 0.082 L atm K-1 mol-1)
1.6 × 10-2
1.6 × 10-5
1.6 × 10-3
1.6 × 10-4
The pH of a saturated solution of a metal hydroxide of formula X(OH)2 is 12.0 at 298 K. What is the solubility product of a metal hydroxide at 298 K (in mol3 L-3)?
5 × 10-7
2 × 10-6
1 × 10-7
5 × 10-5
The IUPAC name of the complex [Co(NH3)2(H2O)4]Cl3 is
diaminetetraaquacobalt (III) trichlodde
diaminetetraaquacobalt (II) chloride
diaminetetraaquacobalt (III) chloride
tetraaquadiaminecobalt (III) trichloride
The products obtained by the ozonolysis of 2-ethylbut-1-ene are
propanone and ethanal
methanal and 3-pentanone
ethanal and 3-pentanone
butanal and ethanal
When but-2-yne is treated with Na in liquid ammonia
cis-2-butene is obtained
trans-2-butene is formed
n-butane is the major product
it rearranges to but-1-yne