OCR GCSE Combined Science A · J250
Specification C3.3k, WS1.3h · Biology Paper 1, Biology Paper 2, Chemistry Paper 1, Chemistry Paper 2, Physics Paper 1, Physics Paper 2
Revise: Measuring pHYou need the meter and probe, reference solutions of known pH for calibration, distilled water for rinsing, and a clean beaker containing the sample.
- Revise: Error Identification
Checking an instrument against known reference values and adjusting it or its readings where necessary.