Indicator solution in Horrocks apparatus contains
**Question:** Indicator solution in Horrocks apparatus contains
A. pH indicator solution
B. Blood
C. Calcium chloride solution
D. Nitric acid
**Correct Answer:** A. pH indicator solution
**Core Concept:** Horrocks apparatus is a tool used in clinical chemistry to measure pH levels in various samples, including blood. The key component in the apparatus is the indicator solution, which helps indicate the change in pH upon addition of the sample.
**Why the Correct Answer is Right:** The pH indicator solution serves as a crucial component in the Horrocks apparatus. It contains dyes or substances that change color at specific pH ranges, allowing the user to visually determine the pH level of the sample. In this case, the correct answer (A) is "pH indicator solution" because it contains the substances that change color based on pH, enabling accurate pH measurement.
**Why Each Wrong Option is Incorrect:**
B. Blood: This is not the component of the Horrocks apparatus; it is the sample being tested. Blood is only relevant as a component of the sample being analyzed.
C. Calcium chloride solution: This substance is unrelated to the Horrocks apparatus and is not used in pH measurement. Calcium chloride has its own clinical applications but not in the context of pH measurement.
D. Nitric acid: Nitric acid is a strong acid and does not serve as an indicator solution in the Horrocks apparatus. Indicator solutions contain dyes or substances that change color based on pH, which is why option A is correct and options B-D are incorrect.
**Clinical Pearl / High-Yield Fact:** The pH indicator solution is essential for accurate pH measurement in the Horrocks apparatus, as it contains substances that change color at specific pH ranges. Understanding the correct use of an indicator solution helps medical professionals in interpreting pH values correctly, which is critical in various clinical settings, including diagnosing and managing acid-base disorders, monitoring blood pH during anesthesia, and assessing pH levels in various bodily fluids.