g You have decided to add ethidium bromide directly to your agarose solution before you pour you gel. You have a stock solution of 6 mg/ml and you want a final concentration of 0.5 g/ml in your 50 ml agarose solution. Calculate how much of the stock solution you will need to make add to the agarose solution to give you a final concentration of 0.5 g/ml.

4.17mL of the stock solution of ethidium bromide must be added in the 50mL agarose solution

Explanation:

You want to dilute the ethidium bromide from 6mg/mL to 0.5mg/mL, that is:

6mg/mL / 0.5mg/mL = 12 times the stock solution must be diluted.

As the final volume of the solution is 50mL, you must add:

50mL / 12 =

4.17mL of the stock solution of ethidium bromide must be added in the 50mL agarose solution

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answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.