Question
Q6, A student investigated food dyes using paper chromatography, This is the method used 1. Put a spot of food colouring on the start line. Put spots of four separate dyes, A B, C and D on the start line. 2. place the bottom of the paper in water and leave it for start line inutes. Figure 1 shows the apparatus the student used. (a) Write down two mistakes the student made in setting up the experiment and explain what problems one of the mistakes would cause. __ __ Mistake 2 __ __ disappointed
Answer
4.6
(237 Votes)
Scarlett
Advanced · Tutor for 1 years
Answer
Mistake 1: The spots of food colouring and the dyes were not above the water level when the paper was placed in the water. Problem caused by Mistake 1: The dyes will dissolve directly into the water instead of being carried up the paper by capillary action, preventing the separation of the different components of the dyes.Mistake 2: The student used water instead of a non-polar solvent. Problem caused by Mistake 2: Water, being a polar solvent, may not effectively separate all the components of the dyes, especially if some of the components are non-polar. A non-polar solvent would have been more effective in separating a wider range of components.
Explanation
## Step 1: Identify Mistake 1The first mistake the student made was not ensuring that the spots of food colouring and the dyes were above the water level when the paper was placed in the water. ## Step 2: Explain the Problem Caused by Mistake 1If the spots are below the water level, the dyes will dissolve directly into the water instead of being carried up the paper by capillary action. This would prevent the separation of the different components of the dyes, defeating the purpose of the chromatography experiment.## Step 3: Identify Mistake 2The second mistake the student made was not using a non-polar solvent instead of water. ## Step 4: Explain the Problem Caused by Mistake 2Water, being a polar solvent, may not effectively separate all the components of the dyes, especially if some of the components are non-polar. A non-polar solvent would have been more effective in separating a wider range of components.