A + B ⇌ 2 B {\displaystyle A+B\rightleftharpoons 2B}
d [ A ] d t = − k + [ A ] [ B ] + k − [ B ] 2 {\displaystyle {\frac {\mathrm {d} [A]}{\mathrm {d} t}}=-k_{+}[A][B]+k_{-}[B]^{2}}
d [ B ] d t = k + [ A ] [ B ] − 2 k − [ B ] 2 + k − [ B ] 2 = k + [ A ] [ B ] − k − [ B ] 2 {\displaystyle {\frac {\mathrm {d} [B]}{\mathrm {d} t}}=k_{+}[A][B]-2k_{-}[B]^{2}+k_{-}[B]^{2}=k_{+}[A][B]-k_{-}[B]^{2}}
[ A ] = [ A ] 0 + [ B ] 0 − [ B ] {\displaystyle [A]=[A]_{0}+[B]_{0}-[B]}
d [ B ] d t = k + ( [ A ] 0 + [ B ] 0 − [ B ] ) [ B ] − k − [ B ] 2 {\displaystyle {\frac {\mathrm {d} [B]}{\mathrm {d} t}}=k_{+}([A]_{0}+[B]_{0}-[B])[B]-k_{-}[B]^{2}}
d [ B ] d t = ( k + ( [ A ] 0 + [ B ] 0 ) − ( k + + k − ) [ B ] ) [ B ] {\displaystyle {\frac {\mathrm {d} [B]}{\mathrm {d} t}}=(k_{+}([A]_{0}+[B]_{0})-(k_{+}+k_{-})[B])[B]}
d [ B ] d t = ( k + + k − ) ( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] ) [ B ] {\displaystyle {\frac {\mathrm {d} [B]}{\mathrm {d} t}}=(k_{+}+k_{-})({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]}
∫ 1 ( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] ) [ B ] d [ B ] d t d t = ∫ ( k + + k − ) d t {\displaystyle \int {\frac {1}{({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]}}{\frac {\mathrm {d} [B]}{\mathrm {d} t}}\mathrm {d} t=\int (k_{+}+k_{-})\mathrm {d} t}
1 ( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] ) [ B ] ≡ 1 k + k + + k − ( [ A ] 0 + [ B ] 0 ) ( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] ) + 1 k + k + + k − ( [ A ] 0 + [ B ] 0 ) [ B ] {\displaystyle {\frac {1}{({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]}}\equiv {\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])}}+{\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})[B]}}}
∫ ( 1 k + k + + k − ( [ A ] 0 + [ B ] 0 ) ( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] ) + 1 k + k + + k − ( [ A ] 0 + [ B ] 0 ) [ B ] ) d [ B ] d t d t = ∫ ( k + + k − ) d t {\displaystyle \int ({\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])}}+{\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})[B]}}){\frac {\mathrm {d} [B]}{\mathrm {d} t}}\mathrm {d} t=\int (k_{+}+k_{-})\mathrm {d} t}
1 k + k + + k − ( [ A ] 0 + [ B ] 0 ) ∫ ( 1 k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] + 1 [ B ] ) d [ B ] d t d t = ∫ ( k + + k − ) d t {\displaystyle {\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})}}\int ({\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]}}+{\frac {1}{[B]}}){\frac {\mathrm {d} [B]}{\mathrm {d} t}}\mathrm {d} t=\int (k_{+}+k_{-})\mathrm {d} t}
1 k + k + + k − ( [ A ] 0 + [ B ] 0 ) ln ( [ B ] k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] ) = ( k + + k − ) t + c {\displaystyle {\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})}}\ln {({\frac {[B]}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]}})}=(k_{+}+k_{-})t+c}
Substituting initial conditions of [ B ] = [ B ] 0 {\displaystyle [B]=[B]_{0}} and t = 0 {\displaystyle t=0} ,
c = 1 k + k + + k − ( [ A ] 0 + [ B ] 0 ) ln ( [ B ] 0 k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] 0 ) {\displaystyle c={\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})}}\ln {({\frac {[B]_{0}}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]_{0}}})}}
1 k + k + + k − ( [ A ] 0 + [ B ] 0 ) ln ( ( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] 0 ) [ B ] ( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] ) [ B ] 0 ) = ( k + + k − ) t {\displaystyle {\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})}}\ln {({\frac {({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]_{0})[B]}{({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]_{0}}})}=(k_{+}+k_{-})t}
( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] 0 ) [ B ] ( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] ) [ B ] 0 = e k + ( [ A ] 0 + [ B ] 0 ) t {\displaystyle {\frac {({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]_{0})[B]}{({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]_{0}}}=e^{k_{+}([A]_{0}+[B]_{0})t}}
( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] 0 ) [ B ] = ( k + k + + k − ( [ A ] 0 + [ B ] 0 ) − [ B ] ) [ B ] 0 e k + ( [ A ] 0 + [ B ] 0 ) t {\displaystyle ({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]_{0})[B]=({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]_{0}e^{k_{+}([A]_{0}+[B]_{0})t}}
( [ A ] 0 [ B ] 0 + 1 − k + + k − k + ) [ B ] = ( [ A ] 0 + [ B ] 0 − k + + k − k + [ B ] ) e k + ( [ A ] 0 + [ B ] 0 ) t {\displaystyle ({\frac {[A]_{0}}{[B]_{0}}}+1-{\frac {k_{+}+k_{-}}{k_{+}}})[B]=([A]_{0}+[B]_{0}-{\frac {k_{+}+k_{-}}{k_{+}}}[B])e^{k_{+}([A]_{0}+[B]_{0})t}}
( [ A ] 0 [ B ] 0 − k − k + ) e − k + ( [ A ] 0 + [ B ] 0 ) t [ B ] = ( ( [ A ] 0 + [ B ] 0 ) − k + + k − k + [ B ] ) {\displaystyle ({\frac {[A]_{0}}{[B]_{0}}}-{\frac {k_{-}}{k_{+}}})e^{-k_{+}([A]_{0}+[B]_{0})t}[B]=(([A]_{0}+[B]_{0})-{\frac {k_{+}+k_{-}}{k_{+}}}[B])}
( ( [ A ] 0 [ B ] 0 − k − k + ) e − k + ( [ A ] 0 + [ B ] 0 ) t + k + + k − k + ) [ B ] = [ A ] 0 + [ B ] 0 {\displaystyle (({\frac {[A]_{0}}{[B]_{0}}}-{\frac {k_{-}}{k_{+}}})e^{-k_{+}([A]_{0}+[B]_{0})t}+{\frac {k_{+}+k_{-}}{k_{+}}})[B]=[A]_{0}+[B]_{0}}
[ B ] = [ A ] 0 + [ B ] 0 ( [ A ] 0 [ B ] 0 − k − k + ) e − k + ( [ A ] 0 + [ B ] 0 ) t + 1 + k − k + {\displaystyle [B]={\frac {[A]_{0}+[B]_{0}}{({\frac {[A]_{0}}{[B]_{0}}}-{\frac {k_{-}}{k_{+}}})e^{-k_{+}([A]_{0}+[B]_{0})t}+1+{\frac {k_{-}}{k_{+}}}}}}
[ A ] = ( [ A ] 0 + [ B ] 0 ) ( ( [ A ] 0 [ B ] 0 − k − k + ) e − k + ( [ A ] 0 + [ B ] 0 ) t + 1 + k − k + − 1 ) ( [ A ] 0 [ B ] 0 − k − k + ) e − k + ( [ A ] 0 + [ B ] 0 ) t + 1 + k − k + {\displaystyle [A]={\frac {([A]_{0}+[B]_{0})(({\frac {[A]_{0}}{[B]_{0}}}-{\frac {k_{-}}{k_{+}}})e^{-k_{+}([A]_{0}+[B]_{0})t}+1+{\frac {k_{-}}{k_{+}}}-1)}{({\frac {[A]_{0}}{[B]_{0}}}-{\frac {k_{-}}{k_{+}}})e^{-k_{+}([A]_{0}+[B]_{0})t}+1+{\frac {k_{-}}{k_{+}}}}}}
[ A ] = ( [ A ] 0 + [ B ] 0 ) ( ( [ A ] 0 [ B ] 0 − k − k + ) e − k + ( [ A ] 0 + [ B ] 0 ) t + k − k + ) ( [ A ] 0 [ B ] 0 − k − k + ) e − k + ( [ A ] 0 + [ B ] 0 ) t + 1 + k − k + {\displaystyle [A]={\frac {([A]_{0}+[B]_{0})(({\frac {[A]_{0}}{[B]_{0}}}-{\frac {k_{-}}{k_{+}}})e^{-k_{+}([A]_{0}+[B]_{0})t}+{\frac {k_{-}}{k_{+}}})}{({\frac {[A]_{0}}{[B]_{0}}}-{\frac {k_{-}}{k_{+}}})e^{-k_{+}([A]_{0}+[B]_{0})t}+1+{\frac {k_{-}}{k_{+}}}}}}
![{\displaystyle {\frac {\mathrm {d} [A]}{\mathrm {d} t}}=-k_{+}[A][B]+k_{-}[B]^{2}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d58c88d7f98fa3edddb4f4fe41c5b2a7c2063945)
![{\displaystyle {\frac {\mathrm {d} [B]}{\mathrm {d} t}}=k_{+}[A][B]-2k_{-}[B]^{2}+k_{-}[B]^{2}=k_{+}[A][B]-k_{-}[B]^{2}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/cdc65b4ce332d04a68032d6849e95b61ea5aa4e2)
![{\displaystyle [A]=[A]_{0}+[B]_{0}-[B]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/5d2b24797cd407b1eb04d18771831fca6a92078b)
![{\displaystyle {\frac {\mathrm {d} [B]}{\mathrm {d} t}}=k_{+}([A]_{0}+[B]_{0}-[B])[B]-k_{-}[B]^{2}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/0b4478758f626dcbb3fddd79119c0bcef697b4e0)
![{\displaystyle {\frac {\mathrm {d} [B]}{\mathrm {d} t}}=(k_{+}([A]_{0}+[B]_{0})-(k_{+}+k_{-})[B])[B]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/4018501fb69539a64e598e2161e22dd8e28a5ffa)
![{\displaystyle {\frac {\mathrm {d} [B]}{\mathrm {d} t}}=(k_{+}+k_{-})({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/4e2163a73cac4ac7951777d1d4894ccbbdaa19e6)
![{\displaystyle \int {\frac {1}{({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]}}{\frac {\mathrm {d} [B]}{\mathrm {d} t}}\mathrm {d} t=\int (k_{+}+k_{-})\mathrm {d} t}](https://wikimedia.org/api/rest_v1/media/math/render/svg/2169705a6bf6ba8020c00a14c4c3628f06962633)
![{\displaystyle {\frac {1}{({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]}}\equiv {\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])}}+{\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})[B]}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/296cd80ffda5ac0d31af83206eb6eb3a65463242)
![{\displaystyle \int ({\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])}}+{\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})[B]}}){\frac {\mathrm {d} [B]}{\mathrm {d} t}}\mathrm {d} t=\int (k_{+}+k_{-})\mathrm {d} t}](https://wikimedia.org/api/rest_v1/media/math/render/svg/08ed704c34246b6e19879a4c4915a461202cbe96)
![{\displaystyle {\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})}}\int ({\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]}}+{\frac {1}{[B]}}){\frac {\mathrm {d} [B]}{\mathrm {d} t}}\mathrm {d} t=\int (k_{+}+k_{-})\mathrm {d} t}](https://wikimedia.org/api/rest_v1/media/math/render/svg/2c41f7e7b8e4cdf7c573973349a190ec373c0967)
![{\displaystyle {\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})}}\ln {({\frac {[B]}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]}})}=(k_{+}+k_{-})t+c}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d7258042566cf9f229ba48302406b26589fde7c9)
![{\displaystyle [B]=[B]_{0}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/d19f89e2314914cfbe99495ba6a6b6c96b5d8d5d)
and 
,
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![{\displaystyle {\frac {1}{{\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})}}\ln {({\frac {({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]_{0})[B]}{({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]_{0}}})}=(k_{+}+k_{-})t}](https://wikimedia.org/api/rest_v1/media/math/render/svg/8a165db40de4acbde99eb3432b91736d92d6d6c4)
![{\displaystyle {\frac {({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]_{0})[B]}{({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]_{0}}}=e^{k_{+}([A]_{0}+[B]_{0})t}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/61d5b68975cb115a752bb5820788a6eadab76eb3)
![{\displaystyle ({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B]_{0})[B]=({\frac {k_{+}}{k_{+}+k_{-}}}([A]_{0}+[B]_{0})-[B])[B]_{0}e^{k_{+}([A]_{0}+[B]_{0})t}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/a66fc9b99a038415783ceded6226ee68090e23b3)
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![{\displaystyle [B]={\frac {[A]_{0}+[B]_{0}}{({\frac {[A]_{0}}{[B]_{0}}}-{\frac {k_{-}}{k_{+}}})e^{-k_{+}([A]_{0}+[B]_{0})t}+1+{\frac {k_{-}}{k_{+}}}}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/163e05fc7f14e6b67f11e2353aa16b917046ebab)
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