Principle

The inversion reaction of saccharose, which is catalysed by protons, produces invert sugar, which is a mixture of glucose and fructose. The reaction is accompanied by a change in the optical rotation of the system. Glucose rotates the polarisation plane of linearly polarised light to the right, while inverted sugar rotates it to the left. A half-shade polarimeter is used for the measurement of the change in the angle of rotation of polarised light during the inversion reaction of saccharose over time.

Benefits

• Easy entry into polarimetry
• Combination of methodological skills and theoretical knowledge

Tasks

1. Determine the specific rotation of saccharose and lactose by measuring the rotation angle of solutions of various concentrations.
2. Determine the rate constant of the inversion of saccharose.

Learning objectives

• Reaction rate
• First order reaction
• Polarimetry
• Optical rotation

Necessary accessories

• Precision balance 620g/0.001g