🔍 Key Concepts

• Ammonia (NH₃) is a basic (alkaline) gas • Litmus paper changes color depending on whether a substance is acidic or basic • Difference between red litmus and blue litmus color changes when exposed to bases

💭 Think About

• Think about what happens to red litmus paper when it comes in contact with a base or alkaline gas like ammonia • Recall the original color of pink/red litmus and which direction (toward acidic or basic) the color change goes when exposed to a base • Mentally review the standard rule: acids affect one litmus color, bases affect the other—how does that apply here?

✅ Before You Answer

• Confirm that ammonia is a base, not an acid • Recall which litmus (red or blue) is used to test for bases specifically • Verify the final color of red/pink litmus in a basic environment before choosing among orange, red, purple, or blue