When sulphur dioxide is passed in an acidified K2Cr2O7 solution, the oxidation state of sulphur is changed from
+4 to 0
+4 to +2
+ 4 to +6
+6 to +4
For the decomposition of a compound AB at 600 K, the following data were obtained
[AB] mol dm-3 | Rate of decomposition of AB in mol dm-3 |
0.20 | 2.75 × 10-8 |
0.40 | 11.0 × 10-8 |
0.60 | 24.75 × 10-8 |
The order for the decomposition of AB is
1.5
0
1
2
A miscible mixture of C6H6 + CHCl3 can be separated by
sublimation
distillation
filtration
crystallisation
The heat of combustion of carbon to CO2 is -393.5 kJ/ mol. The heat released upon formation of 35.2 gm of CO2 from carbon and oxygen gas is:
+315 kJ
-31.5 kJ
-315 kJ
+31.5 kJ
C.
-315 kJ
Given,
Heat of combustion of C to CO2 = -393.5 kJ/ mol
Molecular mass of CO2 = 12 + 16 × 2 = 44 gm
C (s) + O2 (g) → CO2 (g); H = -393.5 kJ
Heat of formation of (1 mole) 44 gm
CO2 = -393.5 kJ
Heat of formation of (1 mole) 1g
CO2 =
Heat of formation of (1 mole)
35.2 g CO2 =
= -314.8 kJ
= -315 kJ
Which of the following substances acts as an oxidising as well as a reducing agent ?
Na2O
SnCl2
Na2O2
NaNO2
3ClO-(aq) → ClO- + 2Cl is an example of
Oxidation reaction
reduction reaction
disproportionation reaction
decomposition reaction