The element with atomic number 55 belongs to which block of the periodic table?
s-block
p-block
d-block
f-block
To which block is related an element having electronic configuration 1s2, 2s2 2p6, 3s2 3p6 3d10, 4s1 in the periodic table?
s-block
p-block
d-block
f-block
The electronic configuration of an element is 1s2, 2s2, 2p6, 3s2 3p6, 3d10, 4s2 4p3. Its properties would be similar to which of the following elements?
Boron
Oxygen
Nitrogen
Chlorine
The formula of phosphate of a metal, M is MPO4. The formula of its nitrate will be
M NO3
M (NO3)2
M (NO3)3
M2(NO3)3
The formula of phosphate of a metal, M is M NH4PO4. The formula of its sulphate will be
M SO4
M (SO4)2
M2SO4
M2 (SO4)3
A 100 mL solution of 0.1 N HCl was titrated with 0.2 N NaOH solution.The titration was discontinued after adding 30 mL of NaOH solution. The remaining titration was completed by adding 025 N KOH solution. The volume of KOH required for completing the titration is
16 mL
32 mL
35 mL
70 mL
On which of the following principles hydrogen bomb is based?
Nuclear fission
Nuclear fusion
Artificial radioactivity
Natural radioactivity
B.
Nuclear fusion
Hydrogen bomb is based on the principle of nuclear fusion. In hydrogen bomb centre is surrounded by a mixture of deterium (1H2) and lithium-6-isotopes [3Li6].
The reaction taking place in a hydrogen bomb may be represented as follows:-
Fusion (in centre) → Heat + neutrons
3Li6 + 0n1 → 1H3 + 2He4 + 4.78 MeV
1H2 + 1H3 → 2He4 + 0n1 + 17.6 MeV
1H2 + 1H2 → 2He3 + 0n1 + 3.3 MeV
1H3 + 1H3 → 2He4 + 20n1 + 11 MeV
In the combustion of 2.0 g of methane, 25 kcal heat is liberated, heat of combustion of methane would be
100 kcal
200 kcal
300 kcal
400 kcal