The standard enthalpies of formation of A(NH3), B(CO2), C(HI) and D(SO2) are - 46.19, -393.4, +24.94 and -296.9 kJ mol1 respectively. The increasing order of their
stability is
B < D < A < C
C < A < D < B
D < B < C < A
A < C < D < B
Which of the following pair of metals is purified by van- Arkel method?
Zr and Ti
Ag and Au
Ni and Fe
Ga and In
In Fischer-Ringe's method of separation of nobles gas mixture from air, ......... is used
90% CaC2 + 10% CaCl2
coconut charcol
soda lime + potash solution
90% CaCO3 + 10% urea
A.
90% CaC2 + 10% CaCl2
In Fischer Ringe's method, air free from moisture and CO2 is passed over a heated mixture (800°C) of 90% CaC2 + 10% CaCl2 in an iron tube, when following reactions take place
CaC2 + N2 CaCN2 + C
2C + O 2CO
C + O2 CO2
2CaC2 + 3CO2 2CaCO3 + 5C
CuO + CO Cu + CO2
CO2 gas is now absorbed by KOH solution. Thus, a mixture of inert gas is obtained.
In Duma's method of estimation of nitrogen, 0.35 g of an organic compound gave 55 mL of nitrogen collected at 300 K temperature and 715 mm pressure. The percentage composition of nitrogen in the compound would be (Aqueous tension at 300 K = 15 mm)
16.45
17.45
14.45
15.45
Which of the following is not correct?
Ammonia is used as refrigerant
A mixture of Ca(CN)2 and C is known as nitrolim
A mixture of Ca(H2PO4),% and CaSO4.2H20 is known as superphosphate of lime
Hydrolysis of NCl3 gives NH3 and HOCl
Which one of the following is aromatic?
Cyclopentadienyl cation
Cyclooctatetraene
Cycloheptatriene
Cycloheptatrienylcation
The complexes [Co(NH3)6][Cr(CN)6] and [Cr(NH3)6][Co(CN)6] are the examples of which type of isomerism?
Ionisation isomerism
Coordination isomerism
Geometrical isomerism
Linkage isomerism
Which of the following compounds is soluble in benzene but almost insoluble in water?
C2H5OH
CH3CO2H
CH3CHO
C6H5NO2
Which one of the following reactions does not form gaseous product?
PbO2 + H2O2
Acidified KMnO4 + H2O2
PbS + H2O2
Cl2 + H2O2