The ion which is not tetrahedral in shape is
BF4-
NH4+
Cu(NH3)42+
NiCl42-
C.
Cu(NH3)42+
Among all the given options, Cu(NH3)42+ is not tetrahedral in shape. Its electronic configuration is 3d9 4s0.
One electron is shifted from 3d to 4p orbital.
Among the following the weakest base is
C6H5CH2NH2
C6H5CH2NHCH3
O2NCH2NH2
CH3NHCHO
D.
CH3NHCHO
Among all the given options, CH3NHCHO is the weakest base. This is because carbonyl group exerts an electro withdrawal effect due to which basicity at N-atom decreases.
Which one of the following has S° greater than zero?
CaO(s) + CO2(g) CaCO3(s)
NaCl(aq) NaCl(s)
NaNO3(s) Na+(aq) + NO3-(aq)
N2(g) + 3H2(g) 2NH3(g)
C.
NaNO3(s) Na+(aq) + NO3-(aq)
Among the following options, option c is correct. It is because the number of product species is greater than the number of reactant species. So it leads to positive value of entropy.
MnO (1 mole) in neutral aqueous medium is disproportionated to
2/3 mole of MnO and 1/3 mole of MnO2
1/3 mole of MnO and 2/3 mole of MnO2
1/3 mole of Mn2O7 and 1/3 mole of MnO2
2/3 mole of Mn2O7 and 1/3 mole of MnO2
A.
2/3 mole of MnO and 1/3 mole of MnO2
MnO(1 mole) in neutral aqueous medium is disproportionated to 2/3 mole of MnO and 1/3 mole of MnO2.
3MnO + 2H2O → MnO2 (s) + 2MnO + 4OH-
For one mole-
MnO + H2O → MnO2 (s) + MnO + OH-
One gram sample of NH4NO3 is decomposed in a bomb calorimeter. The temperature of the calorimeter increases by 6.12 K. The heat capacity of the system is 1.23 kJ/g/deg. What is the molar heat of decomposition for NH4NO3 ?
-7.53 kJ/mol
-398.1 kJ/mol
-16.1 kJ/mol
-602 kJ/mol
D.
-602 kJ/mol
Heat of decomposition, E = msT = 1 × 1.23 × 6.12 = 7.5276 kJ
Molar heat of decompsoition for NH4NO3 = 7.5276 × 80 = 602.2 kJ/mol
The paramagnetic species is
KO2
SiO2
TiO2
BaO2
A.
KO2
KO2 is a superoxide of potassium containing superoxide ion, O2- which has three electron bond. Thus, it can be represented as-
The presence of one unpaired electron in three electron bond makes this ion paramagnetic.
Among the following the strongest acid is
CH3COOH
C6H5COOH
m-CH3OC6H4COOH
p-CH3OC6H4COOH
C.
m-CH3OC6H4COOH
Among all the given options, strongest acid is m-CH3OC6H4COOH.
-OCH3 group displays electron withdrawing acid strengthening inductive effect at the meta position but at the para position, an electron releasing acid weakening resonance effect operates (which at this position outweighs the inductive effect).
Which of the following compounds possesses the C-H bond with the lowest bond dissociation energy?
Toluene
Benzene
n-Pentane
2,2-Dimethylpropane
A.
Toluene
Bond dissociation energy for C - H are given below in the given molecules
C6H5CH3 - 85 kcal/mol
C6H6 - 110 kcal/mol
CH3CH2CH2CH2CH3 - 98 kcal/mol
C(CH3)4 - 92 kcal/mol
Which of the following are arranged in the decreasing order of dipole moment?
CH3Cl, CH3Br, CH3F
CH3Br, CH3Cl, CH3F
CH3Cl, CH3Br, CH3F
CH3Br, CH3F, CH3Cl
B.
CH3Br, CH3Cl, CH3F
Among all the given options, option b is correct.
The values of dipole moments of methyl halides:
CH3F - 1.51 D ; CH3Cl - 1.56 D; CH3Br - 1.4 D; CH3I - 1.29 D
Therefore, CH3Cl > CH3F > CH3Br > CH3I
Intermolecular hydrogen bonding is strongest in
methylamine
phenol
formaldehyde
methanol
D.
methanol
Methanol has strongest intermolecular hydrogen bonding because it has more -OH group.
---H - O(CH3) ----H - O(CH3) ----H - O(CH3)
With the increase of electronegativity and decrease in size of the atom to which hydrogen is colvalently linked, the strength of the hydrogen bond increases.