By scientific question, it really just means create a normal question. The example would be:
How will gas be affected if the temperature in an enclosed container is to be changed?
There are mannnyyy ways how to write a question for this, you just have to make sure you write what you are changing and how you are changing it, oh and make it sound smart haha.
Answer:
159 mg caffeine is being extracted in 60 mL dichloromethane
Explanation:
Given that:
mass of caffeine in 100 mL of water = 600 mg
Volume of the water = 100 mL
Partition co-efficient (K) = 4.6
mass of caffeine extracted = ??? (unknown)
The portion of the DCM = 60 mL
Partial co-efficient (K) = ![\frac{C_1}{C_2}](https://tex.z-dn.net/?f=%5Cfrac%7BC_1%7D%7BC_2%7D)
where;
solubility of compound in the organic solvent and
= solubility in aqueous water.
So; we can represent our data as:
÷ ![(\frac{B_{(mg)}}{100mL} )](https://tex.z-dn.net/?f=%28%5Cfrac%7BB_%7B%28mg%29%7D%7D%7B100mL%7D%20%29)
Since one part of the portion is A and the other part is B
A+B = 60 mL
A+B = 0.60
A= 0.60 - B
4.6=
÷ ![(\frac{B_{(mg)}}{100mL})](https://tex.z-dn.net/?f=%28%5Cfrac%7BB_%7B%28mg%29%7D%7D%7B100mL%7D%29)
4.6 = ![\frac{(\frac{0.6-B(mg)}{60mL} )}{(\frac{B_{(mg)}}{100mL})}](https://tex.z-dn.net/?f=%5Cfrac%7B%28%5Cfrac%7B0.6-B%28mg%29%7D%7B60mL%7D%20%29%7D%7B%28%5Cfrac%7BB_%7B%28mg%29%7D%7D%7B100mL%7D%29%7D)
4.6 ×
=
4.6 B
= 0.6 - B
2.76 B = 0.6 - B
2.76 + B = 0.6
3.76 B = 0.6
B = ![\frac{0.6}{3.76}](https://tex.z-dn.net/?f=%5Cfrac%7B0.6%7D%7B3.76%7D)
B = 0.159 g
B = 159 mg
∴ 159 mg caffeine is being extracted from the 100 mL of water containing 600 mg of caffeine with one portion of in 60 mL dichloromethane.
It is called exothermic reaction because it releases heat and light and it is called combustion reaction because it is reacting and is being oxidised by O2 to MgO.
It can also be called as oxidation reaction since Mg is oxidised to MgO.