Open the Settings app on your phone
Tap Accounts or Passwords & accounts
Select Google
Choose the Google account you want to remove
Tap Remove account
Confirm the action if prompted
If needed, open the Gmail app
Tap your profile picture
Tap Manage accounts on this device
Select the account
Tap Remove from this device
If you want to sign out of Chrome, open Chrome
Tap the three-dot menu
Tap Settings
Tap your Google account
Tap Sign out and turn off sync
Confirm if prompted