19 g of a mixture containing NaHCO3 and Na2CO3 on complete heating liberated 1.12 L of CO2 at STP. The weight of the remaining solid was 15.9 g. What is the weight (in g) of Na2CO3 in the mixture before heating?
8.4
15.9
4.0
10.6
Under which one of the following conditions do real gases approach the ideal gas behaviour?
Low temperature and high pressure
High temperature and high pressure
High temperature and low pressure
Low temperature and low pressure
C.
High temperature and low pressure
Real gases approach the ideal gas behaviour at high temperature and low pressure.
Which one of the following is the ratio of the lowering of vapour pressure of 0.1 M , aqueous solutions of BaCl2, NaCl and Al2SO3 respectively?
3 : 2 : 5
5 : 2 : 3
5 : 3 : 2
2 : 3 : 5
Which one of the following exhibits enantiomerism?
BeCH2-CH2-CH2-CH2Br
H3C-CH(Br)-CH2-CH2-CH3
H3C-CH2-CH2-CH2Br
H3C-CH2-CBr2-CH3
Nitrobenzene on reduction using zinc in alkaline medium results in X. The number of sigma (σ) and pi () bonds in X is-
24 σ, 7
24 σ, 6
27 σ, 7
24 σ, 6
Which property among the following is same for both hydrogen and deuterium molecules?
Bond energy
Melting point
Boiling point
Bond length
In which of the following reactions hydrogen is not liberated?
Reaction of fused NaOH with C
Reaction of NaOH with sulphur
Heating the concentrated NaOH with Si
Reaction of zinc with NaOH
Which one of the following statements is not correct?
Moissan boron is amorphous
The reaction between boron and concentrated HNO3, gives N2O.
Amorphous boron on heating with oxygen forms B2O3.
Boron is a non-conductor of electricity.
Which one of the following is a correct set?
Diamond, sp2
Graphite, sp3
Diamond, sp
Graphite, sp2