In some cases, imines exist in equilibrium with enamines. as the imine is more stable because it has stronger bonds, it will generally be present in greater amount at equilibrium. in the boxes below, draw a mechanism to show the conversion of an enamine to an imine in the presence of catalytic acid ("tosic acid," tsoh). note that "tso–" is the conjugate base of tosic acid.

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally