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) = 
where; 
solubility of compound in the organic solvent and 
= solubility in aqueous water.
So; we can represent our data as:
÷ 
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=
÷ 
4.6 = 
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 = 
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.
Right answer is B . Trust me .
Answer:
four covalent bonds
Explanation:
A carbon atom would form 4 covalent bonds.
For a covalent bond to be formed, an atom would share its valence electrons with another. In this process, each atom would require unpaired electrons for this bond to be formed. The number of available unpaired electrons would represent the number of electrons needed to complete the outer energy level of the atom.
In a carbon atom, we have no lone pair of electrons and 4 unpaired electrons. When these 4 electrons are shared with those of other atoms, they produce a complete octet which perfectly mimics the noble gases.
