Cambridge Secondary (7-9). Stage 7. MCE Science. Workbook - Unit 8: Acids and Alkalis - Question 38

Jason uses red and blue litmus paper to test a solution of sodium hydroxide. What changes does he observe? Tick (✓) the two correct answers.
- The blue litmus paper turns red.
- The blue litmus paper stays blue.
- The red litmus paper turns blue.
- The red litmus paper stays red.