Ijmb Model Questions Vol1 2019 Biology Question 3

Practice practical question 3 from the 2019 Ijmb Model Questions Vol1 Biology examination. This question covers Nutrition .

Ijmb Model Questions Vol1 2019 Biology Practical
Topic: Nutrition
Question 3 IJMB_MODEL_QUESTIONS_VOL1 • 2019 • BIOLOGY • practical

A student is investigating the carbohydrate content of a commercial fruit juice using the Benedict’s test. The student prepares glucose standard solutions of known concentrations (0.2, 0.4, 0.6 and 0.8 g dL⁻¹) and records the absorbance of the orange‑red precipitate at 540 nm after heating. The absorbance readings obtained are 0.12, 0.24, 0.35 and 0.46 respectively. The student then tests 10.0 mL of the fruit juice, obtains an absorbance of 0.38 and records the volume of precipitate formed as 2.5 mL. Answer the following:

Question Parts

( a )
Construct the calibration curve (absorbance versus concentration) and determine the equation of the best‑fit straight line using the method of least squares (assume a linear relationship).
( b )
Using the equation obtained in (a), calculate the concentration of carbohydrate (as glucose equivalent) in the fruit‑juice sample (in g dL⁻¹).
( c )
The student diluted the juice 1 : 1 with distilled water before the test. Determine the original carbohydrate concentration in the undiluted juice.
( d )
Discuss two possible sources of systematic error in this experiment and how each could affect the calculated carbohydrate content.

Detailed Solution & Marking Scheme

Get the step-by-step solution, key points required by examiners and detailed marking guidance through the Edcrib AI Tutor.

Reveal Answer

About This Question

This is Ijmb Model Questions Vol1 2019 Biology Question 3. It is one of the practical questions from the 2019 Ijmb Model Questions Vol1 Biology examination.

The question covers Nutrition .

View More Ijmb Model Questions Vol1 2019 Biology Questions More Ijmb Model Questions Vol1 Practice Questions Back to Questions

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Chat with Support