From the Chrome application, tap the Open tabs icon at the top right of the screen.
Scroll up or down (the tabs are stacked vertically), then tap the tab that you want to switch to.
You can also swipe to switch tabs. While viewing an open tab:
Swipe from the right-hand edge of the screen to the left to go to the next tab in the list.
Swipe from the left-hand edge of the screen to the right to go to the previous tab in the list.