The correct answer is option C, 5.02 x 10²² carbon atoms
Atomic mass of C = 12 g/mol
According to Avogadro, 1 mole of C has 6.023 x 10²³C atoms
Now 1 mole of C is equal to 12 g
Therefore, 12 g of C = 6.023 x 10²³ C atoms
1 g of C = 
C atoms = 5.02 x 10²² C atoms
It is important to have the correct bond angles of the different atoms and the shape of the molecule due to following reasons;
Among other properties the polarity of compounds mainly depend upon the shape and bond angles of that particular compound. For example, considering the molecule of water, we already know that it is a polar molecule with partially positive hydrogen atoms and partially negative oxygen atoms and acts as universal solvent. The bond angle in water is about 104.5° with a Bent geometry. Unlike carbon dioxide (CO₂) which has Linear structure with bond angle 180° and is non-polar in nature therefore, the bent geometry in water is responsible for the polarity.
Other properties which can also be predicted by predicting the bond angles along with molecular geometries are;
i) Magnetism
ii) Phase of matter
iii) Color
iv) Reactivity
v) Biological activities <em>e.t.c</em>
An aqueous solution in a 55 gallon (208 l drum), characterized by minimal buffering capacity, received 4kg of phenol and 1.5 kg of sodium phenate. What is the ph of the solution. The pka of phenol = 9.98. Mw of phenol and sodium phenate are 94 g/mol and 116 g/mol, respectively.
Volume of solution = 55 gallons = 208.2 L [ 1 gallon = 3.78 L]
moles of phenol = mass / molar mass = 4000 g / 94 = 42.55 moles
moles of sodium phenate = mass / molar mass = 1500 / 116 = 12.93 moles
pKa of phenol = 9.98
We know that the pH of buffer is calculated using Hendersen Hassalbalch's equation
pH = pKa + log [salt] / [acid]
volume is same for both the sodium phenate and phenol has we can directly take the moles of each in the formula
pH = 9.98 + log [12.93 / 42.55] = 9.46
