In base vs. acid titration, at the end point methyl orange is present as

56.0 L of nitrogen gas is mixed with excess hydrogen gas and it is found that 20 L of ammonia gas is produced. The volume of unused nitrogen gas is found to be _________ L.

When the excited electron of a H atom from n = 5 drops to the ground state, the maximum number of emission lines observed are _____________.

While performing a thermodynamics experiment, a student made the following observations.

HCl + NaOH $$\to$$ NaCl + H₂O $$\Delta$$H = $$-$$57.3 kJ mol^$$-$$1

CH₃COOH + NaOH $$\to$$ CH₃COONa + H₂O $$\Delta$$H = $$-$$55.3 kJ mol^$$-$$1

The enthalpy of ionization of CH₃COOH as calculated by the student is _____________ kJ mol^$$-$$1. (nearest integer)