when the heat of reaction at constant pressure is -2.5 x 103 cal can entropy change is 7.4 cal deg-1 at 25oC, the reaction is predicted as
reversible
Spontaneous
non -spontaneous
Irreversible
The volume of water to be added to 100 cm3 of 0.5 NH2SO4 to get decinormal concentration is
100 cm3
450 cm3
500 cm3
400 cm3
Solid NaHCO3 will be neutralised by 40.0 mL of 0.1 M H2SO4 solution. What would be the weight of solid NaHCO3 in gram?
0.672 g
6.07 g
17 g
20 g
A.
0.672 g
The required neutralisation reaction is
2NaHCO3 + H2SO4 Na2SO4 + 2H2O + 2CO2
Number of moles in 2NaHCO3 and Na2SO4 are 2 and 1 respectively.
Therefore, 2NaHCO3 = 168 gm and Na2SO4 = 98 gm
Moles of H2SO4 = M VmL = 40.0 0.1 = 4m- mole. Also, it can written as m- moles of NaHCO3 when neutralised = 4 2 = 8m-moles.
m-mole =
8 =
w = = 0.672 gms.
A solution with negative deviation among the following is
ethanol-acetone
chlorobenzene-bromobenzene
chloroform-acetone
benzene-toluene
For an ideal binary liquid solution with in which relation between Xx (mole fraction of X in liquid phase) and Yx ( mole fraction of Y in liquid and vapour phase respectively.
Xx > YX
Xx = Yx
XX, YX, XY and YY cannot be correlated
In an experiment, addition of 4.0 mL of 0.005 M BaCl2 to 16.0 mL of arsenious sulphide sol just causes complete coagulation in 2 h. The flocculating value of the effective ion is
Ba2+, 1.0
Ba2+, 2.0
Cl-, 1.0
Cl-, 2.0
The aqueous solution of an unknown sodium salt gives the following reactions.
I. It decolourises a solution of iodine in potassium iodide.
II. It gives white turbidity with dil.HCl solution.
III. It gives a white precipitate with AgNO3 solution which changes colours and finally becomes black on standing.
The unknown sodium salt is
Sodium thiosulphate
sodium bisulphite
sodium sulphite
sodium sulphide
Which of the following would exert maximum osmotic pressure?
Decinormal aluminium sulphate
Decinormal barium chloride
Decinormal sodium chloride
A solution obtained by mixing equal volumes of (b) and (c) and filtering
The vapour pressure of 100g water reduces from 3000 Nm-2 to 2985 Nm-2 when 5g of substance 'X' is dissolved in it. Substance 'X' is
methanol
glucose
carbon dioxide
cannot predict