35.4 ml of HCl is required for the neutralization of a solution containing 0.275 g of sodium hydroxide. The normality of hydrochloric acid is ?
0.97 N
0.142 N
0.194 N
0.244 N
The value of amu is which of the following ?
1.57 × 10-24 kg
1.66 × 10-24 kg
1.99 × 10-23 kg
1.66 × 10-27 kg
Which one of the following has unit positive charge and 1 amu mass ?
Electron
Neutron
Proton
None of these
Which one of the following pair shows Buffer's solution?
NaCl + NaOH
CH3COONa + CH3COOH
CH3COOH + CH3COONH4
H2SO4 + CuSO4
By dissolving 5 g substance in 50 g of water, the decrease in freezing point is 1.2°C. The gram molal depression is 1.85°C. The molecular weight of substance is :
105.4
118.2
137.2
154.2
The radius of hydrogen atom is 0.53 Å. The radius of 3Li2+ is of:
1.27 Å
0.17 Å
0.57 Å
0.99 Å
B.
0.17 Å
The radius of hydrogen atom = 0.53 Å.
3Li+2 ion consists of only 1 electron but it has 3 protons in its nucleus. Hence, its electron fall is three times more attracted from nucleus as compared to hydrogen atom. Thus, the radius of 3Li+2 is = = 0.17 Å
The correct sequence of hybridisation of methane, ethene and acetylene is :
sp, sp2, sp3
sp2, sp3, sp
sp3, sp2, sp
sp3, sp, sp2