The major product [B] in the following reactions is :

250 mL of a waste solution obtained from the workshop of a goldsmith contains 0.1 M AgNO₃ and 0.1 M AuCl. The solution was electrolyzed at 2V by passing a current of 1A for 15 minutes. The metal/metals electrodeposited will be

[ $$E_{A{g^ + }/Ag}^0$$ = 0.80 V, $$E_{A{u^ + }/Au}^0$$ = 1.69 V ]

Five moles of an ideal gas at 1 bar and 298 K is expanded into vacuum to double the volume. The work done is :

The shortest wavelength of H atom in the Lyman series is $$\lambda $$₁. The longest wavelength in the Balmar series of He⁺ is :