An organic compound contains C = 40% O = 53.3% and H = 6.60% . The empirical formula of the compound is
CH2O
CHO
CH4O2
C2H2O
The most suitable method for separation of 1 : 1 mixture of ortho and para- nitro phenol is
Sublimation
Chromatography
Crystallization
Steam distillation
Which of the following compounds does not show Lassaigne's test for nitrogen?
Urea
Hydrazine
Phenyl hydrazine
Azobenzene
If two compounds have the same empirical formula but different molecular formulae, they must have
Different percentage composition
Different molecular weights
Same viscosity
Same vapour density
Which of the following will have least hindered rotation about carbon-carbon bond?
Ethane
Ethylene
Acetylene
Hexachloroethane
The kind of valency that exists in CaH2 and C2H2 is
Electrovalency in CaH2 and covalency in C2H2
Electrovalency in both
Covalency in CaH2 and electrovalency in C2H2
Covalency in both
Which of the following compounds will show metamerism?
CH3COOC2H5
C2H5 — S — C2H5
CH3 — O —CH3
CH3 — O —C2H5
The Lassaigne's extract is boiled with dilute HNO3 before testing for halogens because
Ag2S is insoluble in HNO3
AgCN is soluble in HNO3
Na2S and NaCN are decomposed by HNO3
Silver halides are soluble in HNO3
Anthracene is purified by
Filtration
Distillation
Two elements X (atomic weight = 75) and Y (atomic weight = 16 ) combine to give a compound having 75.8 % X. The formula of the compound is
XY
X2Y
X2Y2
X2Y3
