Which of the following combination will form an electrovalent bond ?
P and Cl
NH3 and BF3
H and Ca
H and S
How many moles of Al2(SO4)3 a would be in 50 gm of the substance ?
0.083 mol
0.952 mol
0.481 mol
0.140 mol
The solubility of CaF2 in pure water is 2.3 × 10-4 mol dm3. Its solubility product will be:
4.6 × 10-4
4.6 × 10-8
6.9 × 10-12
4.9 × 10-11
Which is the correct order of electronegativity?
F > N < O < C
F > N > O > C
F > N > O < C
F < N < O = C
The radius of hydrogen atom in the ground state is 0.53 Å. The radius of Li2+ ion (atomic number = 3) in a similar state is :
0.176 Å
0.30 Å
0.53 Å
1.23 Å
C-H bond energy is about 101 kcal/ mol for methane, ethane and other alkanes but is only 77 kcal/ mol for C-H bond of CH3 in toluene. This is because :
of inductive effect due to -CH3 in toluene
of the presence of benzene ring in toluene
of resonance among the structures of benzyl radical in toluene
aromaticity of toluene
Hess's law is used to calculate :
enthalpy of reaction
entropy of reaction
work done in reaction
All of the above
A.
enthalpy of reaction
Hess's law states that enthalpy changes during and process are independent of path. So, this law is used in calculating enthalpy.