The atomic masses of He and Ne are 4 and 20 a.m.u., respectively. The value of the de Broglie wavelength of He gas at –73^oC is “M” times that of the de Broglie wavelength of Ne at 727^oC. M is

The total number of lone-pairs of electrons in melamine is

The standard enthalpies of formation of CO₂(g), H₂O(l) and glucose(s) at 25^oC are –400 kJ/mol, –300 kJ/mol and –1300 kJ/mol, respectively. The standard enthalpy of combustion per gram of glucose at 25^oC is

The initial rate of hydrolysis of methyl acetate (1M) by a weak acid (HA, 1M) is 1/100^th of that of a strong acid (HX, 1M), at 25^oC. The K_a of HA is