Mexican Shrimp Cocktail

Ingredients

• 2 medium tomatoes, seeded and finely chopped
• 1 medium onion, finely chopped
• 1/2 cup chopped fresh cilantro
• 1 tablespoon grated lime zest
• 1/2 teaspoon salt
• 1 bottle (12-1/2 ounces) mandarin natural flavor soda
• 1-1/2 cups Clamato juice
• 1/4 cup lime juice
• 1/4 cup ketchup
• 1-1/2 pounds peeled and deveined cooked shrimp (100-150 per pound)
• 2 avocados, finely chopped
• Tortilla chips