Web viewChemistry and Light. ... To do this we will use some of the following chemistry equipment below – can you identify the items, and draw 2D representations of each?

Chemistry and Light

There are lots of examples of where we use light and chemistry:

input output EXAMPLELight Reaction Photochemistry

Heat Light Flame tests

Reaction Light Chemiluminescence

Light Light (different colour)

fluorescence

The emission of light from a chemical, when it is irradiated with light of a different energy:

Substance ABSORBS energy from LIGHT – ‘excited’

Energy is released as LIGHT emission = fluorescence

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Fluorescence (sometimes called photoluminescence)

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Today we are going to extract some fluorescent chemicals from household items.

To do this we will use some of the following chemistry equipment below – can you identify the items, and draw 2D representations of each?


Practical Experiment:

AIM: To make a selection of fluorescent solutions

ATTENTION: wear safety goggles – we are going to use ethanol

You will need:BeakerFilter paperFunnelConical flasksSpatulaEthanolWater

ACTIVITY

We are going to extract fluorescent molecules from some common items that you may come across at home:

Equipment for the extraction

DISSOLVE the fluorescent compound in a SOLVENT, in a beaker, to form a SOLUTION.

FITLER this solution to remove the RESIDUE, and collect the FILTRATE:


Make up a fluorescent solution of vitamin B2 and another solution of your choice:

1. Make up a fluorescent solution of riboflavin (vitamin B2):- Empty a capsule of vitamin B2 into a beaker, with and dissolve it in 50 mL of water,

and stir - Pour the mixture into a filter funnel, and collect the liquid in the funnel at the bottom- Use a pipette to collect some of this liquid into a sample vial, put the lid on it, and

look at this under the UV lightWhat light is it absorbing?What type of light is it emitting?

2. Or Make up a fluorescent solution of chlorophyll:- Take a handful of spinach leaves, put into sample bag- Pour enough ethanol into the bag to cover the spinach leaves- Scrunch the leaves in the bag and in the ethanol for a few minutes- Pour the mixture into a filter funnel, and collect the green liquid in the funnel at the

bottom- Use a pipette to collect some of this liquid into a sample vial, put the lid on it, and


If you have time:

3. Make up a fluorescent solution of optical brightener:- Take a teaspoon of washing powder, and dissolve it in 50 mL of water- Pour the mixture into a filter funnel, and collect the liquid in the funnel at the bottom- Use a pipette to collect some of this liquid into a sample vial, put the lid on it, and


4. Or Make up a fluorescent solution of curcumin:- Take a teaspoon of turmeric, and dissolve it in 50 mL of ethanol- Pour the mixture into a filter funnel, and collect the liquid in the funnel at the bottom- Use a pipette to collect some of this liquid into a sample vial, put the lid on it, and



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Web viewChemistry and Light. ... To do this we will use some of the following chemistry equipment below – can you identify the items, and draw 2D representations of each?