We study the 't Hooft coupling $g_{t}$ and the mass splitting of the ground-state baryons in a chiral quark model inspired by the large $N_{c}$ QCD. Depending on $g_{t}$ the Hartree wavefunction of light quark in baryons is used to map the mass hyperfine splittings for the octet and decuplet baryons. The 't Hooft coupling $g_{t}$ that reproduces the data of baryon masses is determined to be around $1.57$, which is small in the sense that $g_{t}^{2}/(4\pi N_{c})\ll $$1$.
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