Macroscopic synchronization was investigated experimentally in the Belousov-Zhabotinsky reaction with a two-dimensional lattice arrangement of coupled chemical oscillators. The natural frequency of each oscillator was distributed randomly and the spacing distance d between beads was varied, where the coupling strength between two oscillators was controlled by changing d. At small d beyond a certain critical value, the oscillators synchronized spontaneously with each other. Global synchronization in the lattice was described as a function of d. The critical coupling strength for global synchronization depends on the total number of oscillators. When noisy light was applied uniformly to whole oscillators, the order of synchronization was maximized at optimal noise intensity: noise synchronization was observed.