A fictitious element X has an average atomic mass of 122.118 u. Element X has two naturally occuring isotopes. The most abundant isotope has an isotopic mass of 121.624 u and a relative abundance of 66.16%. Calculate the isotopic mass of the least abundant isotope.

Amixture initially contains a, b, and c in the following concentrations: [a] = 0.300 m , [b] = 1.05 m , and [c] = 0.550 m . the following reaction occurs and equilibrium is established: a+2b⇌c at equilibrium, [a] = 0.140 m and [c] = 0.710 m . calculate the value of the equilibrium constant, kc.