Demonstrate how you can prepare 250ml 0.25M hydrogen peroxide from a solution of 20g/100ml of hydrogen peroxide.

Determine the volume of the initial solution,  

V

1

, to produce the required solution. We do this by applying the dilution equation,

M

1

V

1

=

M

2

V

2

where M is the concentration and V is the volume, while the subscripts respectively depicts the initial and required solutions. Now, we must express the concentration of the initial solution in terms of moles per liter, wherein we use the conversion factors such as the molar mass, 34.015 g/mol, and 1000 mL/L. We proceed converting the concentration.

M

1

=

20

g

1000

m

L

÷

34.015

g

/

m

o

l

×

1000

m

L

/

L

≈

5.88

M

Now, we are given the following values:

M

2

=

0.25

M

V

2

=

250

m

L

We proceed with the solution by applying the dilution equation and then plugging in the given values.

M

1

V

1

=

M

2

V

2

V

1

=

M

2

V

2

M

1

V

1

=

(

0.25

M

)

(

250

m

L

)

5.88

M

V

1

≈

11

m

L

Therefore, we need to take  

11

m

L

of the initial solution and dilute it to the desired volume to produce the required solution.

that's the explanation but, this helps if ur in higher classes though :>

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.