The pair of compound which cannot exists together in solution is
NaHCO3 and NaOH
Na2CO3 and NHCO3
Na2CO3 and NaOH
NaHCO3 and NaCl
A.
NaHCO3 and NaOH
Acidic salt (NaHCO3) and base (NaOH) cannot exist together in solution.
4.6 x 1022 atoms of an element weigh 13.8g. The atomic weight of that element is
290
180
34.4
10.4
B.
180
Number of lone pair (s) in XeOF4 is/are
0
2
1
3
C.
1
The number of lone pair in XeOF4 is one (1). The structure of XeOF4 is given as follows :
Which of the following has the smallest number of molecules ?
0.1 mole of CO2 gas
11.2 L of CO2 gas at STP
22 g of CO2 gas
22.4 x 103 mL of CO2 gas at STP
A.
0.1 mole of CO2 gas
(a) 0.1 mole of CO2
= 0.5 mole of CO2
(c) = 0.5 mole of CO2
(d) = 1 mole of CO2
Hence, the number of moles of CO2 is least ie, 0.1.
Which one ofthe following compounds has sp2 hybridisation ?
CO2
SO2
N2O
CO
B.
SO2
In SO2 molecule, S is sp2-hybridised
S(16) = 1s2, 2s2, 2p6, 3s2, 3p4
In homogeneous catalysis
the reactants, catalyst and products are in the same phase.
the catalyst and reactants are in the same phase.
the catalyst and products are in the same phase.
the reactants and products are in the same phase.
B.
the catalyst and reactants are in the same phase.
Homogenous catalysis - When the reactants and catalyst are in the same phase, the catalysis is known as homogenous catalysis.
Example:
Identify the least stable ion amongst the following.
Li-
Be-
B-
C-
C.
B-
Li-= 1s2, 2s2 (In it all sub-shells are saturated so, it is stable).
Be- = 1s2, 2s2, 2p1(very much less stable).
B- = 1s2, 2s2, 2p2 (less stable)
C- = 1s2, 2s2, 2p3 (stable due to presence of half-filled 2p-subshell).
A liquid is in equilibrium with its vapour at it's boiling point. On the average, the molecules in two phases have equal
inter- molecular forces
potential energy
kinetic energy
total energy
C.
kinetic energy
In liquid vapour, equilibrium the rate at which molecules escape from the liquid surface to gaseous phase equals to rate at which molecules in the gas phase strike the surface and becomes the part of liquid. Hence, the molecules in the two phases have equal kinetic energy.
For the chemical reaction 3X(g)+ Y(g) X3Y (g), the amount of X3Y at equilibrium is affected by
temperature and pressure
temperature only
pressure only
temperature, pressure and catalyst
B.
temperature only
Equilibrium is affected by temperature and pressure due to change in heat as well as change in volume of substances.
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