Hallo Raghunathan,

still need an answer?
4051 can be good enough for your application, but it depends.
At a time where there were no multi channel ADC developers used mulitplexers like HI-506 or MPC507. They are specialized for this job and so important that very many companies produced them.
Compared to 4051 they have powerful protection circuits and they are optimized in topics like 'isolation'. Why isolation is needed? Well, an electronic switch is never really closed or opened. There is always unavoidable stray capacitance, which drastically decreases high frequency off isolation. To give you an example, I will show you how big stray capacitance is across an opened (non-closed) FET switch:

MC14051: up to 0.47pF
HI-508: 0.1pF
MPC800: 0.02pF

So, modern high speed CMOS analog multiplexer have much better high frequency off isolation than 4051. But if your signal is low pass filtered in such a way that there is no high frequency content, then, of course, simple 4051 is sufficient (and soo much cheaper).
The best way to avoid off isolation problems is to have the inputs of multiplexer driven by low ohmic impedances.
Whether your application suffers from too much high frequency off isolation can easily be tested. Make a ground connection at selected input of multiplexer and have a look what happens. There should nothing else than 'silence'. (Like in a professional 30W amplifier...)

Bye,
Kai