The most stable compound is
LiF
LiCl
LiBr
LiI
A.
LiF
The electronegativity of halogen is as :
F > Cl > Br > I
Among alkali metals the electropositive character increases as :
Li < Na < K < Rb < Cs
Hence, LiF is the most stable compound.
A gas mixture contains O2 and N2 in the ratio of 1 : 4 by weight. The ratio of their number of molecules is
1 : 8
1 : 4
3 : 16
7 : 32
D.
7 : 32
The ratio of O2 and N2 by weight is 1: 4
Therefore, the ratio of O2 and N2 by moles =
= 7 : 32
Hence, the ratio of the number of molecules is 7 : 32.
When copper reacts with hot and conc. H2SO4 gives
H2
N2
O2
SO2
D.
SO2
When copper reacts with hot and conc. H2SO4, SO2 is produced.
Cu + 2H2SO4 CuSO4 + SO2 + 4H2O
The change in entropy for the fusion of 1 mole of ice is [mp of ice = 273 K, molar enthalpy of fusion for ice= 6.0 kJ mol-1]
11.73 JK-1 mol-1
18.84 JK-1 mol-1
21.97 JK-1 mol-1
24.47 JK-1 mol-1
C.
21.97 JK-1 mol-1
Entropy change of fusion
= 60 x 103 JK mol-1; T = 273 K
Heisenberg uncertainty principle can be explained as
B.
According to Heisenberg uncertainty principle, the product of uncertainty in momentum (P) and in position (x) remains constant. Therefore, it can be explained using the following formula
What is X in the following nuclear reaction?
7N14 + 1H1 8O15 + X
0n1
-1e0
+1e0
D.
X in the following reaction is gamma.
7N14 + 1H1 8O15 +
Neutron is discovered by
Chadwick
Rutherford
Yukawa
Dalton
A.
Chadwick
Neutrons are the particles in an atom that have a neutral charge. These particles were discovered by Chadwick.
BaO2 and ozone reacts to produce
Ba
Ba2O3
BaO
Ba(OH)3
C.
BaO
BaO2 and ozone reacts to produce BaO and oxygen.
BaO2 + O3 BaO + 2O2
The volume of a gas measured at 27C and 1 atm pressure is 10 L. To reduce the volume to 2 L at 1 atm pressure, the temperature required is
60 K
75 K
150 K
225 K
A.
60 K
Here, V1 = 10 L; V2 = 2 L
p1 = 1 atm; p2 = 1 atm
T1 = 300 K; T2 = x
The de-Broglie wavelenght of a particle with mass 1 kg and velocity 100 m/s is
6.6 x 10-33 m
6.6 x 10-36 m
3.3 x 1033 m
3.3 x 10-36 m
B.
6.6 x 10-36 m
The de broglie wavelength of a particle with mass 1 kg and velocity 100 m/s is 6.6 x 10-36 m.
=
= 6.6 x 10-36 m